// SPDX-License-Identifier: GPL-2.0-only
/*
 * tools/testing/selftests/kvm/lib/x86_64/processor.c
 *
 * Copyright (C) 2018, Google LLC.
 */

#include "test_util.h"
#include "kvm_util.h"
#include "../kvm_util_internal.h"
#include "processor.h"

#ifndef NUM_INTERRUPTS
#define NUM_INTERRUPTS 256
#endif

#define DEFAULT_CODE_SELECTOR 0x8
#define DEFAULT_DATA_SELECTOR 0x10

vm_vaddr_t exception_handlers;

/* Virtual translation table structure declarations */
struct pageUpperEntry {
        uint64_t present:1;
        uint64_t writable:1;
        uint64_t user:1;
        uint64_t write_through:1;
        uint64_t cache_disable:1;
        uint64_t accessed:1;
        uint64_t ignored_06:1;
        uint64_t page_size:1;
        uint64_t ignored_11_08:4;
        uint64_t pfn:40;
        uint64_t ignored_62_52:11;
        uint64_t execute_disable:1;
};

struct pageTableEntry {
        uint64_t present:1;
        uint64_t writable:1;
        uint64_t user:1;
        uint64_t write_through:1;
        uint64_t cache_disable:1;
        uint64_t accessed:1;
        uint64_t dirty:1;
        uint64_t reserved_07:1;
        uint64_t global:1;
        uint64_t ignored_11_09:3;
        uint64_t pfn:40;
        uint64_t ignored_62_52:11;
        uint64_t execute_disable:1;
};

void regs_dump(FILE *stream, struct kvm_regs *regs,
               uint8_t indent)
{
        fprintf(stream, "%*srax: 0x%.16llx rbx: 0x%.16llx "
                "rcx: 0x%.16llx rdx: 0x%.16llx\n",
                indent, "",
                regs->rax, regs->rbx, regs->rcx, regs->rdx);
        fprintf(stream, "%*srsi: 0x%.16llx rdi: 0x%.16llx "
                "rsp: 0x%.16llx rbp: 0x%.16llx\n",
                indent, "",
                regs->rsi, regs->rdi, regs->rsp, regs->rbp);
        fprintf(stream, "%*sr8:  0x%.16llx r9:  0x%.16llx "
                "r10: 0x%.16llx r11: 0x%.16llx\n",
                indent, "",
                regs->r8, regs->r9, regs->r10, regs->r11);
        fprintf(stream, "%*sr12: 0x%.16llx r13: 0x%.16llx "
                "r14: 0x%.16llx r15: 0x%.16llx\n",
                indent, "",
                regs->r12, regs->r13, regs->r14, regs->r15);
        fprintf(stream, "%*srip: 0x%.16llx rfl: 0x%.16llx\n",
                indent, "",
                regs->rip, regs->rflags);
}

/*
 * Segment Dump
 *
 * Input Args:
 *   stream  - Output FILE stream
 *   segment - KVM segment
 *   indent  - Left margin indent amount
 *
 * Output Args: None
 *
 * Return: None
 *
 * Dumps the state of the KVM segment given by @segment, to the FILE stream
 * given by @stream.
 */
static void segment_dump(FILE *stream, struct kvm_segment *segment,
                         uint8_t indent)
{
        fprintf(stream, "%*sbase: 0x%.16llx limit: 0x%.8x "
                "selector: 0x%.4x type: 0x%.2x\n",
                indent, "", segment->base, segment->limit,
                segment->selector, segment->type);
        fprintf(stream, "%*spresent: 0x%.2x dpl: 0x%.2x "
                "db: 0x%.2x s: 0x%.2x l: 0x%.2x\n",
                indent, "", segment->present, segment->dpl,
                segment->db, segment->s, segment->l);
        fprintf(stream, "%*sg: 0x%.2x avl: 0x%.2x "
                "unusable: 0x%.2x padding: 0x%.2x\n",
                indent, "", segment->g, segment->avl,
                segment->unusable, segment->padding);
}

/*
 * dtable Dump
 *
 * Input Args:
 *   stream - Output FILE stream
 *   dtable - KVM dtable
 *   indent - Left margin indent amount
 *
 * Output Args: None
 *
 * Return: None
 *
 * Dumps the state of the KVM dtable given by @dtable, to the FILE stream
 * given by @stream.
 */
static void dtable_dump(FILE *stream, struct kvm_dtable *dtable,
                        uint8_t indent)
{
        fprintf(stream, "%*sbase: 0x%.16llx limit: 0x%.4x "
                "padding: 0x%.4x 0x%.4x 0x%.4x\n",
                indent, "", dtable->base, dtable->limit,
                dtable->padding[0], dtable->padding[1], dtable->padding[2]);
}

void sregs_dump(FILE *stream, struct kvm_sregs *sregs,
                uint8_t indent)
{
        unsigned int i;

        fprintf(stream, "%*scs:\n", indent, "");
        segment_dump(stream, &sregs->cs, indent + 2);
        fprintf(stream, "%*sds:\n", indent, "");
        segment_dump(stream, &sregs->ds, indent + 2);
        fprintf(stream, "%*ses:\n", indent, "");
        segment_dump(stream, &sregs->es, indent + 2);
        fprintf(stream, "%*sfs:\n", indent, "");
        segment_dump(stream, &sregs->fs, indent + 2);
        fprintf(stream, "%*sgs:\n", indent, "");
        segment_dump(stream, &sregs->gs, indent + 2);
        fprintf(stream, "%*sss:\n", indent, "");
        segment_dump(stream, &sregs->ss, indent + 2);
        fprintf(stream, "%*str:\n", indent, "");
        segment_dump(stream, &sregs->tr, indent + 2);
        fprintf(stream, "%*sldt:\n", indent, "");
        segment_dump(stream, &sregs->ldt, indent + 2);

        fprintf(stream, "%*sgdt:\n", indent, "");
        dtable_dump(stream, &sregs->gdt, indent + 2);
        fprintf(stream, "%*sidt:\n", indent, "");
        dtable_dump(stream, &sregs->idt, indent + 2);

        fprintf(stream, "%*scr0: 0x%.16llx cr2: 0x%.16llx "
                "cr3: 0x%.16llx cr4: 0x%.16llx\n",
                indent, "",
                sregs->cr0, sregs->cr2, sregs->cr3, sregs->cr4);
        fprintf(stream, "%*scr8: 0x%.16llx efer: 0x%.16llx "
                "apic_base: 0x%.16llx\n",
                indent, "",
                sregs->cr8, sregs->efer, sregs->apic_base);

        fprintf(stream, "%*sinterrupt_bitmap:\n", indent, "");
        for (i = 0; i < (KVM_NR_INTERRUPTS + 63) / 64; i++) {
                fprintf(stream, "%*s%.16llx\n", indent + 2, "",
                        sregs->interrupt_bitmap[i]);
        }
}

void virt_pgd_alloc(struct kvm_vm *vm)
{
        TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Attempt to use "
                "unknown or unsupported guest mode, mode: 0x%x", vm->mode);

        /* If needed, create page map l4 table. */
        if (!vm->pgd_created) {
                vm->pgd = vm_alloc_page_table(vm);
                vm->pgd_created = true;
        }
}

static void *virt_get_pte(struct kvm_vm *vm, uint64_t pt_pfn, uint64_t vaddr,
                          int level)
{
        uint64_t *page_table = addr_gpa2hva(vm, pt_pfn << vm->page_shift);
        int index = vaddr >> (vm->page_shift + level * 9) & 0x1ffu;

        return &page_table[index];
}

static struct pageUpperEntry *virt_create_upper_pte(struct kvm_vm *vm,
                                                    uint64_t pt_pfn,
                                                    uint64_t vaddr,
                                                    uint64_t paddr,
                                                    int level,
                                                    enum x86_page_size page_size)
{
        struct pageUpperEntry *pte = virt_get_pte(vm, pt_pfn, vaddr, level);

        if (!pte->present) {
                pte->writable = true;
                pte->present = true;
                pte->page_size = (level == page_size);
                if (pte->page_size)
                        pte->pfn = paddr >> vm->page_shift;
                else
                        pte->pfn = vm_alloc_page_table(vm) >> vm->page_shift;
        } else {
                /*
                 * Entry already present.  Assert that the caller doesn't want
                 * a hugepage at this level, and that there isn't a hugepage at
                 * this level.
                 */
                TEST_ASSERT(level != page_size,
                            "Cannot create hugepage at level: %u, vaddr: 0x%lx\n",
                            page_size, vaddr);
                TEST_ASSERT(!pte->page_size,
                            "Cannot create page table at level: %u, vaddr: 0x%lx\n",
                            level, vaddr);
        }
        return pte;
}

void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr,
                   enum x86_page_size page_size)
{
        const uint64_t pg_size = 1ull << ((page_size * 9) + 12);
        struct pageUpperEntry *pml4e, *pdpe, *pde;
        struct pageTableEntry *pte;

        TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K,
                    "Unknown or unsupported guest mode, mode: 0x%x", vm->mode);

        TEST_ASSERT((vaddr % pg_size) == 0,
                    "Virtual address not aligned,\n"
                    "vaddr: 0x%lx page size: 0x%lx", vaddr, pg_size);
        TEST_ASSERT(sparsebit_is_set(vm->vpages_valid, (vaddr >> vm->page_shift)),
                    "Invalid virtual address, vaddr: 0x%lx", vaddr);
        TEST_ASSERT((paddr % pg_size) == 0,
                    "Physical address not aligned,\n"
                    "  paddr: 0x%lx page size: 0x%lx", paddr, pg_size);
        TEST_ASSERT((paddr >> vm->page_shift) <= vm->max_gfn,
                    "Physical address beyond maximum supported,\n"
                    "  paddr: 0x%lx vm->max_gfn: 0x%lx vm->page_size: 0x%x",
                    paddr, vm->max_gfn, vm->page_size);

        /*
         * Allocate upper level page tables, if not already present.  Return
         * early if a hugepage was created.
         */
        pml4e = virt_create_upper_pte(vm, vm->pgd >> vm->page_shift,
                                      vaddr, paddr, 3, page_size);
        if (pml4e->page_size)
                return;

        pdpe = virt_create_upper_pte(vm, pml4e->pfn, vaddr, paddr, 2, page_size);
        if (pdpe->page_size)
                return;

        pde = virt_create_upper_pte(vm, pdpe->pfn, vaddr, paddr, 1, page_size);
        if (pde->page_size)
                return;

        /* Fill in page table entry. */
        pte = virt_get_pte(vm, pde->pfn, vaddr, 0);
        TEST_ASSERT(!pte->present,
                    "PTE already present for 4k page at vaddr: 0x%lx\n", vaddr);
        pte->pfn = paddr >> vm->page_shift;
        pte->writable = true;
        pte->present = 1;
}

void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
{
        __virt_pg_map(vm, vaddr, paddr, X86_PAGE_SIZE_4K);
}

static struct pageTableEntry *_vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid,
                                                       uint64_t vaddr)
{
        uint16_t index[4];
        struct pageUpperEntry *pml4e, *pdpe, *pde;
        struct pageTableEntry *pte;
        struct kvm_cpuid_entry2 *entry;
        struct kvm_sregs sregs;
        int max_phy_addr;
        /* Set the bottom 52 bits. */
        uint64_t rsvd_mask = 0x000fffffffffffff;

        entry = kvm_get_supported_cpuid_index(0x80000008, 0);
        max_phy_addr = entry->eax & 0x000000ff;
        /* Clear the bottom bits of the reserved mask. */
        rsvd_mask = (rsvd_mask >> max_phy_addr) << max_phy_addr;

        /*
         * SDM vol 3, fig 4-11 "Formats of CR3 and Paging-Structure Entries
         * with 4-Level Paging and 5-Level Paging".
         * If IA32_EFER.NXE = 0 and the P flag of a paging-structure entry is 1,
         * the XD flag (bit 63) is reserved.
         */
        vcpu_sregs_get(vm, vcpuid, &sregs);
        if ((sregs.efer & EFER_NX) == 0) {
                rsvd_mask |= (1ull << 63);
        }

        TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Attempt to use "
                "unknown or unsupported guest mode, mode: 0x%x", vm->mode);
        TEST_ASSERT(sparsebit_is_set(vm->vpages_valid,
                (vaddr >> vm->page_shift)),
                "Invalid virtual address, vaddr: 0x%lx",
                vaddr);
        /*
         * Based on the mode check above there are 48 bits in the vaddr, so
         * shift 16 to sign extend the last bit (bit-47),
         */
        TEST_ASSERT(vaddr == (((int64_t)vaddr << 16) >> 16),
                "Canonical check failed.  The virtual address is invalid.");

        index[0] = (vaddr >> 12) & 0x1ffu;
        index[1] = (vaddr >> 21) & 0x1ffu;
        index[2] = (vaddr >> 30) & 0x1ffu;
        index[3] = (vaddr >> 39) & 0x1ffu;

        pml4e = addr_gpa2hva(vm, vm->pgd);
        TEST_ASSERT(pml4e[index[3]].present,
                "Expected pml4e to be present for gva: 0x%08lx", vaddr);
        TEST_ASSERT((*(uint64_t*)(&pml4e[index[3]]) &
                (rsvd_mask | (1ull << 7))) == 0,
                "Unexpected reserved bits set.");

        pdpe = addr_gpa2hva(vm, pml4e[index[3]].pfn * vm->page_size);
        TEST_ASSERT(pdpe[index[2]].present,
                "Expected pdpe to be present for gva: 0x%08lx", vaddr);
        TEST_ASSERT(pdpe[index[2]].page_size == 0,
                "Expected pdpe to map a pde not a 1-GByte page.");
        TEST_ASSERT((*(uint64_t*)(&pdpe[index[2]]) & rsvd_mask) == 0,
                "Unexpected reserved bits set.");

        pde = addr_gpa2hva(vm, pdpe[index[2]].pfn * vm->page_size);
        TEST_ASSERT(pde[index[1]].present,
                "Expected pde to be present for gva: 0x%08lx", vaddr);
        TEST_ASSERT(pde[index[1]].page_size == 0,
                "Expected pde to map a pte not a 2-MByte page.");
        TEST_ASSERT((*(uint64_t*)(&pde[index[1]]) & rsvd_mask) == 0,
                "Unexpected reserved bits set.");

        pte = addr_gpa2hva(vm, pde[index[1]].pfn * vm->page_size);
        TEST_ASSERT(pte[index[0]].present,
                "Expected pte to be present for gva: 0x%08lx", vaddr);

        return &pte[index[0]];
}

uint64_t vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr)
{
        struct pageTableEntry *pte = _vm_get_page_table_entry(vm, vcpuid, vaddr);

        return *(uint64_t *)pte;
}

void vm_set_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr,
                             uint64_t pte)
{
        struct pageTableEntry *new_pte = _vm_get_page_table_entry(vm, vcpuid,
                                                                  vaddr);

        *(uint64_t *)new_pte = pte;
}

void virt_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent)
{
        struct pageUpperEntry *pml4e, *pml4e_start;
        struct pageUpperEntry *pdpe, *pdpe_start;
        struct pageUpperEntry *pde, *pde_start;
        struct pageTableEntry *pte, *pte_start;

        if (!vm->pgd_created)
                return;

        fprintf(stream, "%*s                                          "
                "                no\n", indent, "");
        fprintf(stream, "%*s      index hvaddr         gpaddr         "
                "addr         w exec dirty\n",
                indent, "");
        pml4e_start = (struct pageUpperEntry *) addr_gpa2hva(vm, vm->pgd);
        for (uint16_t n1 = 0; n1 <= 0x1ffu; n1++) {
                pml4e = &pml4e_start[n1];
                if (!pml4e->present)
                        continue;
                fprintf(stream, "%*spml4e 0x%-3zx %p 0x%-12lx 0x%-10lx %u "
                        " %u\n",
                        indent, "",
                        pml4e - pml4e_start, pml4e,
                        addr_hva2gpa(vm, pml4e), (uint64_t) pml4e->pfn,
                        pml4e->writable, pml4e->execute_disable);

                pdpe_start = addr_gpa2hva(vm, pml4e->pfn * vm->page_size);
                for (uint16_t n2 = 0; n2 <= 0x1ffu; n2++) {
                        pdpe = &pdpe_start[n2];
                        if (!pdpe->present)
                                continue;
                        fprintf(stream, "%*spdpe  0x%-3zx %p 0x%-12lx 0x%-10lx "
                                "%u  %u\n",
                                indent, "",
                                pdpe - pdpe_start, pdpe,
                                addr_hva2gpa(vm, pdpe),
                                (uint64_t) pdpe->pfn, pdpe->writable,
                                pdpe->execute_disable);

                        pde_start = addr_gpa2hva(vm, pdpe->pfn * vm->page_size);
                        for (uint16_t n3 = 0; n3 <= 0x1ffu; n3++) {
                                pde = &pde_start[n3];
                                if (!pde->present)
                                        continue;
                                fprintf(stream, "%*spde   0x%-3zx %p "
                                        "0x%-12lx 0x%-10lx %u  %u\n",
                                        indent, "", pde - pde_start, pde,
                                        addr_hva2gpa(vm, pde),
                                        (uint64_t) pde->pfn, pde->writable,
                                        pde->execute_disable);

                                pte_start = addr_gpa2hva(vm, pde->pfn * vm->page_size);
                                for (uint16_t n4 = 0; n4 <= 0x1ffu; n4++) {
                                        pte = &pte_start[n4];
                                        if (!pte->present)
                                                continue;
                                        fprintf(stream, "%*spte   0x%-3zx %p "
                                                "0x%-12lx 0x%-10lx %u  %u "
                                                "    %u    0x%-10lx\n",
                                                indent, "",
                                                pte - pte_start, pte,
                                                addr_hva2gpa(vm, pte),
                                                (uint64_t) pte->pfn,
                                                pte->writable,
                                                pte->execute_disable,
                                                pte->dirty,
                                                ((uint64_t) n1 << 27)
                                                        | ((uint64_t) n2 << 18)
                                                        | ((uint64_t) n3 << 9)
                                                        | ((uint64_t) n4));
                                }
                        }
                }
        }
}

/*
 * Set Unusable Segment
 *
 * Input Args: None
 *
 * Output Args:
 *   segp - Pointer to segment register
 *
 * Return: None
 *
 * Sets the segment register pointed to by @segp to an unusable state.
 */
static void kvm_seg_set_unusable(struct kvm_segment *segp)
{
        memset(segp, 0, sizeof(*segp));
        segp->unusable = true;
}

static void kvm_seg_fill_gdt_64bit(struct kvm_vm *vm, struct kvm_segment *segp)
{
        void *gdt = addr_gva2hva(vm, vm->gdt);
        struct desc64 *desc = gdt + (segp->selector >> 3) * 8;

        desc->limit0 = segp->limit & 0xFFFF;
        desc->base0 = segp->base & 0xFFFF;
        desc->base1 = segp->base >> 16;
        desc->type = segp->type;
        desc->s = segp->s;
        desc->dpl = segp->dpl;
        desc->p = segp->present;
        desc->limit1 = segp->limit >> 16;
        desc->avl = segp->avl;
        desc->l = segp->l;
        desc->db = segp->db;
        desc->g = segp->g;
        desc->base2 = segp->base >> 24;
        if (!segp->s)
                desc->base3 = segp->base >> 32;
}


/*
 * Set Long Mode Flat Kernel Code Segment
 *
 * Input Args:
 *   vm - VM whose GDT is being filled, or NULL to only write segp
 *   selector - selector value
 *
 * Output Args:
 *   segp - Pointer to KVM segment
 *
 * Return: None
 *
 * Sets up the KVM segment pointed to by @segp, to be a code segment
 * with the selector value given by @selector.
 */
static void kvm_seg_set_kernel_code_64bit(struct kvm_vm *vm, uint16_t selector,
        struct kvm_segment *segp)
{
        memset(segp, 0, sizeof(*segp));
        segp->selector = selector;
        segp->limit = 0xFFFFFFFFu;
        segp->s = 0x1; /* kTypeCodeData */
        segp->type = 0x08 | 0x01 | 0x02; /* kFlagCode | kFlagCodeAccessed
                                          * | kFlagCodeReadable
                                          */
        segp->g = true;
        segp->l = true;
        segp->present = 1;
        if (vm)
                kvm_seg_fill_gdt_64bit(vm, segp);
}

/*
 * Set Long Mode Flat Kernel Data Segment
 *
 * Input Args:
 *   vm - VM whose GDT is being filled, or NULL to only write segp
 *   selector - selector value
 *
 * Output Args:
 *   segp - Pointer to KVM segment
 *
 * Return: None
 *
 * Sets up the KVM segment pointed to by @segp, to be a data segment
 * with the selector value given by @selector.
 */
static void kvm_seg_set_kernel_data_64bit(struct kvm_vm *vm, uint16_t selector,
        struct kvm_segment *segp)
{
        memset(segp, 0, sizeof(*segp));
        segp->selector = selector;
        segp->limit = 0xFFFFFFFFu;
        segp->s = 0x1; /* kTypeCodeData */
        segp->type = 0x00 | 0x01 | 0x02; /* kFlagData | kFlagDataAccessed
                                          * | kFlagDataWritable
                                          */
        segp->g = true;
        segp->present = true;
        if (vm)
                kvm_seg_fill_gdt_64bit(vm, segp);
}

vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
{
        uint16_t index[4];
        struct pageUpperEntry *pml4e, *pdpe, *pde;
        struct pageTableEntry *pte;

        TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Attempt to use "
                "unknown or unsupported guest mode, mode: 0x%x", vm->mode);

        index[0] = (gva >> 12) & 0x1ffu;
        index[1] = (gva >> 21) & 0x1ffu;
        index[2] = (gva >> 30) & 0x1ffu;
        index[3] = (gva >> 39) & 0x1ffu;

        if (!vm->pgd_created)
                goto unmapped_gva;
        pml4e = addr_gpa2hva(vm, vm->pgd);
        if (!pml4e[index[3]].present)
                goto unmapped_gva;

        pdpe = addr_gpa2hva(vm, pml4e[index[3]].pfn * vm->page_size);
        if (!pdpe[index[2]].present)
                goto unmapped_gva;

        pde = addr_gpa2hva(vm, pdpe[index[2]].pfn * vm->page_size);
        if (!pde[index[1]].present)
                goto unmapped_gva;

        pte = addr_gpa2hva(vm, pde[index[1]].pfn * vm->page_size);
        if (!pte[index[0]].present)
                goto unmapped_gva;

        return (pte[index[0]].pfn * vm->page_size) + (gva & 0xfffu);

unmapped_gva:
        TEST_FAIL("No mapping for vm virtual address, gva: 0x%lx", gva);
        exit(EXIT_FAILURE);
}

static void kvm_setup_gdt(struct kvm_vm *vm, struct kvm_dtable *dt)
{
        if (!vm->gdt)
                vm->gdt = vm_vaddr_alloc_page(vm);

        dt->base = vm->gdt;
        dt->limit = getpagesize();
}

static void kvm_setup_tss_64bit(struct kvm_vm *vm, struct kvm_segment *segp,
                                int selector)
{
        if (!vm->tss)
                vm->tss = vm_vaddr_alloc_page(vm);

        memset(segp, 0, sizeof(*segp));
        segp->base = vm->tss;
        segp->limit = 0x67;
        segp->selector = selector;
        segp->type = 0xb;
        segp->present = 1;
        kvm_seg_fill_gdt_64bit(vm, segp);
}

static void vcpu_setup(struct kvm_vm *vm, int vcpuid)
{
        struct kvm_sregs sregs;

        /* Set mode specific system register values. */
        vcpu_sregs_get(vm, vcpuid, &sregs);

        sregs.idt.limit = 0;

        kvm_setup_gdt(vm, &sregs.gdt);

        switch (vm->mode) {
        case VM_MODE_PXXV48_4K:
                sregs.cr0 = X86_CR0_PE | X86_CR0_NE | X86_CR0_PG;
                sregs.cr4 |= X86_CR4_PAE | X86_CR4_OSFXSR;
                sregs.efer |= (EFER_LME | EFER_LMA | EFER_NX);

                kvm_seg_set_unusable(&sregs.ldt);
                kvm_seg_set_kernel_code_64bit(vm, DEFAULT_CODE_SELECTOR, &sregs.cs);
                kvm_seg_set_kernel_data_64bit(vm, DEFAULT_DATA_SELECTOR, &sregs.ds);
                kvm_seg_set_kernel_data_64bit(vm, DEFAULT_DATA_SELECTOR, &sregs.es);
                kvm_setup_tss_64bit(vm, &sregs.tr, 0x18);
                break;

        default:
                TEST_FAIL("Unknown guest mode, mode: 0x%x", vm->mode);
        }

        sregs.cr3 = vm->pgd;
        vcpu_sregs_set(vm, vcpuid, &sregs);
}

void vm_vcpu_add_default(struct kvm_vm *vm, uint32_t vcpuid, void *guest_code)
{
        struct kvm_mp_state mp_state;
        struct kvm_regs regs;
        vm_vaddr_t stack_vaddr;
        stack_vaddr = vm_vaddr_alloc(vm, DEFAULT_STACK_PGS * getpagesize(),
                                     DEFAULT_GUEST_STACK_VADDR_MIN);

        /* Create VCPU */
        vm_vcpu_add(vm, vcpuid);
        vcpu_set_cpuid(vm, vcpuid, kvm_get_supported_cpuid());
        vcpu_setup(vm, vcpuid);

        /* Setup guest general purpose registers */
        vcpu_regs_get(vm, vcpuid, &regs);
        regs.rflags = regs.rflags | 0x2;
        regs.rsp = stack_vaddr + (DEFAULT_STACK_PGS * getpagesize());
        regs.rip = (unsigned long) guest_code;
        vcpu_regs_set(vm, vcpuid, &regs);

        /* Setup the MP state */
        mp_state.mp_state = 0;
        vcpu_set_mp_state(vm, vcpuid, &mp_state);
}

/*
 * Allocate an instance of struct kvm_cpuid2
 *
 * Input Args: None
 *
 * Output Args: None
 *
 * Return: A pointer to the allocated struct. The caller is responsible
 * for freeing this struct.
 *
 * Since kvm_cpuid2 uses a 0-length array to allow a the size of the
 * array to be decided at allocation time, allocation is slightly
 * complicated. This function uses a reasonable default length for
 * the array and performs the appropriate allocation.
 */
static struct kvm_cpuid2 *allocate_kvm_cpuid2(void)
{
        struct kvm_cpuid2 *cpuid;
        int nent = 100;
        size_t size;

        size = sizeof(*cpuid);
        size += nent * sizeof(struct kvm_cpuid_entry2);
        cpuid = malloc(size);
        if (!cpuid) {
                perror("malloc");
                abort();
        }

        cpuid->nent = nent;

        return cpuid;
}

/*
 * KVM Supported CPUID Get
 *
 * Input Args: None
 *
 * Output Args:
 *
 * Return: The supported KVM CPUID
 *
 * Get the guest CPUID supported by KVM.
 */
struct kvm_cpuid2 *kvm_get_supported_cpuid(void)
{
        static struct kvm_cpuid2 *cpuid;
        int ret;
        int kvm_fd;

        if (cpuid)
                return cpuid;

        cpuid = allocate_kvm_cpuid2();
        kvm_fd = open_kvm_dev_path_or_exit();

        ret = ioctl(kvm_fd, KVM_GET_SUPPORTED_CPUID, cpuid);
        TEST_ASSERT(ret == 0, "KVM_GET_SUPPORTED_CPUID failed %d %d\n",
                    ret, errno);

        close(kvm_fd);
        return cpuid;
}

/*
 * KVM Get MSR
 *
 * Input Args:
 *   msr_index - Index of MSR
 *
 * Output Args: None
 *
 * Return: On success, value of the MSR. On failure a TEST_ASSERT is produced.
 *
 * Get value of MSR for VCPU.
 */
uint64_t kvm_get_feature_msr(uint64_t msr_index)
{
        struct {
                struct kvm_msrs header;
                struct kvm_msr_entry entry;
        } buffer = {};
        int r, kvm_fd;

        buffer.header.nmsrs = 1;
        buffer.entry.index = msr_index;
        kvm_fd = open_kvm_dev_path_or_exit();

        r = ioctl(kvm_fd, KVM_GET_MSRS, &buffer.header);
        TEST_ASSERT(r == 1, "KVM_GET_MSRS IOCTL failed,\n"
                "  rc: %i errno: %i", r, errno);

        close(kvm_fd);
        return buffer.entry.data;
}

/*
 * VM VCPU CPUID Set
 *
 * Input Args:
 *   vm - Virtual Machine
 *   vcpuid - VCPU id
 *
 * Output Args: None
 *
 * Return: KVM CPUID (KVM_GET_CPUID2)
 *
 * Set the VCPU's CPUID.
 */
struct kvm_cpuid2 *vcpu_get_cpuid(struct kvm_vm *vm, uint32_t vcpuid)
{
        struct vcpu *vcpu = vcpu_find(vm, vcpuid);
        struct kvm_cpuid2 *cpuid;
        int max_ent;
        int rc = -1;

        TEST_ASSERT(vcpu != NULL, "vcpu not found, vcpuid: %u", vcpuid);

        cpuid = allocate_kvm_cpuid2();
        max_ent = cpuid->nent;

        for (cpuid->nent = 1; cpuid->nent <= max_ent; cpuid->nent++) {
                rc = ioctl(vcpu->fd, KVM_GET_CPUID2, cpuid);
                if (!rc)
                        break;

                TEST_ASSERT(rc == -1 && errno == E2BIG,
                            "KVM_GET_CPUID2 should either succeed or give E2BIG: %d %d",
                            rc, errno);
        }

        TEST_ASSERT(rc == 0, "KVM_GET_CPUID2 failed, rc: %i errno: %i",
                    rc, errno);

        return cpuid;
}



/*
 * Locate a cpuid entry.
 *
 * Input Args:
 *   function: The function of the cpuid entry to find.
 *   index: The index of the cpuid entry.
 *
 * Output Args: None
 *
 * Return: A pointer to the cpuid entry. Never returns NULL.
 */
struct kvm_cpuid_entry2 *
kvm_get_supported_cpuid_index(uint32_t function, uint32_t index)
{
        struct kvm_cpuid2 *cpuid;
        struct kvm_cpuid_entry2 *entry = NULL;
        int i;

        cpuid = kvm_get_supported_cpuid();
        for (i = 0; i < cpuid->nent; i++) {
                if (cpuid->entries[i].function == function &&
                    cpuid->entries[i].index == index) {
                        entry = &cpuid->entries[i];
                        break;
                }
        }

        TEST_ASSERT(entry, "Guest CPUID entry not found: (EAX=%x, ECX=%x).",
                    function, index);
        return entry;
}

/*
 * VM VCPU CPUID Set
 *
 * Input Args:
 *   vm - Virtual Machine
 *   vcpuid - VCPU id
 *   cpuid - The CPUID values to set.
 *
 * Output Args: None
 *
 * Return: void
 *
 * Set the VCPU's CPUID.
 */
void vcpu_set_cpuid(struct kvm_vm *vm,
                uint32_t vcpuid, struct kvm_cpuid2 *cpuid)
{
        struct vcpu *vcpu = vcpu_find(vm, vcpuid);
        int rc;

        TEST_ASSERT(vcpu != NULL, "vcpu not found, vcpuid: %u", vcpuid);

        rc = ioctl(vcpu->fd, KVM_SET_CPUID2, cpuid);
        TEST_ASSERT(rc == 0, "KVM_SET_CPUID2 failed, rc: %i errno: %i",
                    rc, errno);

}

/*
 * VCPU Get MSR
 *
 * Input Args:
 *   vm - Virtual Machine
 *   vcpuid - VCPU ID
 *   msr_index - Index of MSR
 *
 * Output Args: None
 *
 * Return: On success, value of the MSR. On failure a TEST_ASSERT is produced.
 *
 * Get value of MSR for VCPU.
 */
uint64_t vcpu_get_msr(struct kvm_vm *vm, uint32_t vcpuid, uint64_t msr_index)
{
        struct vcpu *vcpu = vcpu_find(vm, vcpuid);
        struct {
                struct kvm_msrs header;
                struct kvm_msr_entry entry;
        } buffer = {};
        int r;

        TEST_ASSERT(vcpu != NULL, "vcpu not found, vcpuid: %u", vcpuid);
        buffer.header.nmsrs = 1;
        buffer.entry.index = msr_index;
        r = ioctl(vcpu->fd, KVM_GET_MSRS, &buffer.header);
        TEST_ASSERT(r == 1, "KVM_GET_MSRS IOCTL failed,\n"
                "  rc: %i errno: %i", r, errno);

        return buffer.entry.data;
}

/*
 * _VCPU Set MSR
 *
 * Input Args:
 *   vm - Virtual Machine
 *   vcpuid - VCPU ID
 *   msr_index - Index of MSR
 *   msr_value - New value of MSR
 *
 * Output Args: None
 *
 * Return: The result of KVM_SET_MSRS.
 *
 * Sets the value of an MSR for the given VCPU.
 */
int _vcpu_set_msr(struct kvm_vm *vm, uint32_t vcpuid, uint64_t msr_index,
                  uint64_t msr_value)
{
        struct vcpu *vcpu = vcpu_find(vm, vcpuid);
        struct {
                struct kvm_msrs header;
                struct kvm_msr_entry entry;
        } buffer = {};
        int r;

        TEST_ASSERT(vcpu != NULL, "vcpu not found, vcpuid: %u", vcpuid);
        memset(&buffer, 0, sizeof(buffer));
        buffer.header.nmsrs = 1;
        buffer.entry.index = msr_index;
        buffer.entry.data = msr_value;
        r = ioctl(vcpu->fd, KVM_SET_MSRS, &buffer.header);
        return r;
}

/*
 * VCPU Set MSR
 *
 * Input Args:
 *   vm - Virtual Machine
 *   vcpuid - VCPU ID
 *   msr_index - Index of MSR
 *   msr_value - New value of MSR
 *
 * Output Args: None
 *
 * Return: On success, nothing. On failure a TEST_ASSERT is produced.
 *
 * Set value of MSR for VCPU.
 */
void vcpu_set_msr(struct kvm_vm *vm, uint32_t vcpuid, uint64_t msr_index,
        uint64_t msr_value)
{
        int r;

        r = _vcpu_set_msr(vm, vcpuid, msr_index, msr_value);
        TEST_ASSERT(r == 1, "KVM_SET_MSRS IOCTL failed,\n"
                "  rc: %i errno: %i", r, errno);
}

void vcpu_args_set(struct kvm_vm *vm, uint32_t vcpuid, unsigned int num, ...)
{
        va_list ap;
        struct kvm_regs regs;

        TEST_ASSERT(num >= 1 && num <= 6, "Unsupported number of args,\n"
                    "  num: %u\n",
                    num);

        va_start(ap, num);
        vcpu_regs_get(vm, vcpuid, &regs);

        if (num >= 1)
                regs.rdi = va_arg(ap, uint64_t);

        if (num >= 2)
                regs.rsi = va_arg(ap, uint64_t);

        if (num >= 3)
                regs.rdx = va_arg(ap, uint64_t);

        if (num >= 4)
                regs.rcx = va_arg(ap, uint64_t);

        if (num >= 5)
                regs.r8 = va_arg(ap, uint64_t);

        if (num >= 6)
                regs.r9 = va_arg(ap, uint64_t);

        vcpu_regs_set(vm, vcpuid, &regs);

        va_end(ap);
}

void vcpu_dump(FILE *stream, struct kvm_vm *vm, uint32_t vcpuid, uint8_t indent)
{
        struct kvm_regs regs;
        struct kvm_sregs sregs;

        fprintf(stream, "%*scpuid: %u\n", indent, "", vcpuid);

        fprintf(stream, "%*sregs:\n", indent + 2, "");
        vcpu_regs_get(vm, vcpuid, &regs);
        regs_dump(stream, &regs, indent + 4);

        fprintf(stream, "%*ssregs:\n", indent + 2, "");
        vcpu_sregs_get(vm, vcpuid, &sregs);
        sregs_dump(stream, &sregs, indent + 4);
}

struct kvm_x86_state {
        struct kvm_vcpu_events events;
        struct kvm_mp_state mp_state;
        struct kvm_regs regs;
        struct kvm_xsave xsave;
        struct kvm_xcrs xcrs;
        struct kvm_sregs sregs;
        struct kvm_debugregs debugregs;
        union {
                struct kvm_nested_state nested;
                char nested_[16384];
        };
        struct kvm_msrs msrs;
};

static int kvm_get_num_msrs_fd(int kvm_fd)
{
        struct kvm_msr_list nmsrs;
        int r;

        nmsrs.nmsrs = 0;
        r = ioctl(kvm_fd, KVM_GET_MSR_INDEX_LIST, &nmsrs);
        TEST_ASSERT(r == -1 && errno == E2BIG, "Unexpected result from KVM_GET_MSR_INDEX_LIST probe, r: %i",
                r);

        return nmsrs.nmsrs;
}

static int kvm_get_num_msrs(struct kvm_vm *vm)
{
        return kvm_get_num_msrs_fd(vm->kvm_fd);
}

struct kvm_msr_list *kvm_get_msr_index_list(void)
{
        struct kvm_msr_list *list;
        int nmsrs, r, kvm_fd;

        kvm_fd = open_kvm_dev_path_or_exit();

        nmsrs = kvm_get_num_msrs_fd(kvm_fd);
        list = malloc(sizeof(*list) + nmsrs * sizeof(list->indices[0]));
        list->nmsrs = nmsrs;
        r = ioctl(kvm_fd, KVM_GET_MSR_INDEX_LIST, list);
        close(kvm_fd);

        TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_MSR_INDEX_LIST, r: %i",
                r);

        return list;
}

struct kvm_x86_state *vcpu_save_state(struct kvm_vm *vm, uint32_t vcpuid)
{
        struct vcpu *vcpu = vcpu_find(vm, vcpuid);
        struct kvm_msr_list *list;
        struct kvm_x86_state *state;
        int nmsrs, r, i;
        static int nested_size = -1;

        if (nested_size == -1) {
                nested_size = kvm_check_cap(KVM_CAP_NESTED_STATE);
                TEST_ASSERT(nested_size <= sizeof(state->nested_),
                            "Nested state size too big, %i > %zi",
                            nested_size, sizeof(state->nested_));
        }

        /*
         * When KVM exits to userspace with KVM_EXIT_IO, KVM guarantees
         * guest state is consistent only after userspace re-enters the
         * kernel with KVM_RUN.  Complete IO prior to migrating state
         * to a new VM.
         */
        vcpu_run_complete_io(vm, vcpuid);

        nmsrs = kvm_get_num_msrs(vm);
        list = malloc(sizeof(*list) + nmsrs * sizeof(list->indices[0]));
        list->nmsrs = nmsrs;
        r = ioctl(vm->kvm_fd, KVM_GET_MSR_INDEX_LIST, list);
        TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_MSR_INDEX_LIST, r: %i",
                r);

        state = malloc(sizeof(*state) + nmsrs * sizeof(state->msrs.entries[0]));
        r = ioctl(vcpu->fd, KVM_GET_VCPU_EVENTS, &state->events);
        TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_VCPU_EVENTS, r: %i",
                r);

        r = ioctl(vcpu->fd, KVM_GET_MP_STATE, &state->mp_state);
        TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_MP_STATE, r: %i",
                r);

        r = ioctl(vcpu->fd, KVM_GET_REGS, &state->regs);
        TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_REGS, r: %i",
                r);

        r = ioctl(vcpu->fd, KVM_GET_XSAVE, &state->xsave);
        TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_XSAVE, r: %i",
                r);

        if (kvm_check_cap(KVM_CAP_XCRS)) {
                r = ioctl(vcpu->fd, KVM_GET_XCRS, &state->xcrs);
                TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_XCRS, r: %i",
                            r);
        }

        r = ioctl(vcpu->fd, KVM_GET_SREGS, &state->sregs);
        TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_SREGS, r: %i",
                r);

        if (nested_size) {
                state->nested.size = sizeof(state->nested_);
                r = ioctl(vcpu->fd, KVM_GET_NESTED_STATE, &state->nested);
                TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_NESTED_STATE, r: %i",
                        r);
                TEST_ASSERT(state->nested.size <= nested_size,
                        "Nested state size too big, %i (KVM_CHECK_CAP gave %i)",
                        state->nested.size, nested_size);
        } else
                state->nested.size = 0;

        state->msrs.nmsrs = nmsrs;
        for (i = 0; i < nmsrs; i++)
                state->msrs.entries[i].index = list->indices[i];
        r = ioctl(vcpu->fd, KVM_GET_MSRS, &state->msrs);
        TEST_ASSERT(r == nmsrs, "Unexpected result from KVM_GET_MSRS, r: %i (failed MSR was 0x%x)",
                r, r == nmsrs ? -1 : list->indices[r]);

        r = ioctl(vcpu->fd, KVM_GET_DEBUGREGS, &state->debugregs);
        TEST_ASSERT(r == 0, "Unexpected result from KVM_GET_DEBUGREGS, r: %i",
                r);

        free(list);
        return state;
}

void vcpu_load_state(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_x86_state *state)
{
        struct vcpu *vcpu = vcpu_find(vm, vcpuid);
        int r;

        r = ioctl(vcpu->fd, KVM_SET_XSAVE, &state->xsave);
        TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_XSAVE, r: %i",
                r);

        if (kvm_check_cap(KVM_CAP_XCRS)) {
                r = ioctl(vcpu->fd, KVM_SET_XCRS, &state->xcrs);
                TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_XCRS, r: %i",
                            r);
        }

        r = ioctl(vcpu->fd, KVM_SET_SREGS, &state->sregs);
        TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_SREGS, r: %i",
                r);

        r = ioctl(vcpu->fd, KVM_SET_MSRS, &state->msrs);
        TEST_ASSERT(r == state->msrs.nmsrs, "Unexpected result from KVM_SET_MSRS, r: %i (failed at %x)",
                r, r == state->msrs.nmsrs ? -1 : state->msrs.entries[r].index);

        r = ioctl(vcpu->fd, KVM_SET_VCPU_EVENTS, &state->events);
        TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_VCPU_EVENTS, r: %i",
                r);

        r = ioctl(vcpu->fd, KVM_SET_MP_STATE, &state->mp_state);
        TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_MP_STATE, r: %i",
                r);

        r = ioctl(vcpu->fd, KVM_SET_DEBUGREGS, &state->debugregs);
        TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_DEBUGREGS, r: %i",
                r);

        r = ioctl(vcpu->fd, KVM_SET_REGS, &state->regs);
        TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_REGS, r: %i",
                r);

        if (state->nested.size) {
                r = ioctl(vcpu->fd, KVM_SET_NESTED_STATE, &state->nested);
                TEST_ASSERT(r == 0, "Unexpected result from KVM_SET_NESTED_STATE, r: %i",
                        r);
        }
}

bool is_intel_cpu(void)
{
        int eax, ebx, ecx, edx;
        const uint32_t *chunk;
        const int leaf = 0;

        __asm__ __volatile__(
                "cpuid"
                : /* output */ "=a"(eax), "=b"(ebx),
                  "=c"(ecx), "=d"(edx)
                : /* input */ "0"(leaf), "2"(0));

        chunk = (const uint32_t *)("GenuineIntel");
        return (ebx == chunk[0] && edx == chunk[1] && ecx == chunk[2]);
}

uint32_t kvm_get_cpuid_max_basic(void)
{
        return kvm_get_supported_cpuid_entry(0)->eax;
}

uint32_t kvm_get_cpuid_max_extended(void)
{
        return kvm_get_supported_cpuid_entry(0x80000000)->eax;
}

void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits)
{
        struct kvm_cpuid_entry2 *entry;
        bool pae;

        /* SDM 4.1.4 */
        if (kvm_get_cpuid_max_extended() < 0x80000008) {
                pae = kvm_get_supported_cpuid_entry(1)->edx & (1 << 6);
                *pa_bits = pae ? 36 : 32;
                *va_bits = 32;
        } else {
                entry = kvm_get_supported_cpuid_entry(0x80000008);
                *pa_bits = entry->eax & 0xff;
                *va_bits = (entry->eax >> 8) & 0xff;
        }
}

struct idt_entry {
        uint16_t offset0;
        uint16_t selector;
        uint16_t ist : 3;
        uint16_t : 5;
        uint16_t type : 4;
        uint16_t : 1;
        uint16_t dpl : 2;
        uint16_t p : 1;
        uint16_t offset1;
        uint32_t offset2; uint32_t reserved;
};

static void set_idt_entry(struct kvm_vm *vm, int vector, unsigned long addr,
                          int dpl, unsigned short selector)
{
        struct idt_entry *base =
                (struct idt_entry *)addr_gva2hva(vm, vm->idt);
        struct idt_entry *e = &base[vector];

        memset(e, 0, sizeof(*e));
        e->offset0 = addr;
        e->selector = selector;
        e->ist = 0;
        e->type = 14;
        e->dpl = dpl;
        e->p = 1;
        e->offset1 = addr >> 16;
        e->offset2 = addr >> 32;
}

void kvm_exit_unexpected_vector(uint32_t value)
{
        ucall(UCALL_UNHANDLED, 1, value);
}

void route_exception(struct ex_regs *regs)
{
        typedef void(*handler)(struct ex_regs *);
        handler *handlers = (handler *)exception_handlers;

        if (handlers && handlers[regs->vector]) {
                handlers[regs->vector](regs);
                return;
        }

        kvm_exit_unexpected_vector(regs->vector);
}

void vm_init_descriptor_tables(struct kvm_vm *vm)
{
        extern void *idt_handlers;
        int i;

        vm->idt = vm_vaddr_alloc_page(vm);
        vm->handlers = vm_vaddr_alloc_page(vm);
        /* Handlers have the same address in both address spaces.*/
        for (i = 0; i < NUM_INTERRUPTS; i++)
                set_idt_entry(vm, i, (unsigned long)(&idt_handlers)[i], 0,
                        DEFAULT_CODE_SELECTOR);
}

void vcpu_init_descriptor_tables(struct kvm_vm *vm, uint32_t vcpuid)
{
        struct kvm_sregs sregs;

        vcpu_sregs_get(vm, vcpuid, &sregs);
        sregs.idt.base = vm->idt;
        sregs.idt.limit = NUM_INTERRUPTS * sizeof(struct idt_entry) - 1;
        sregs.gdt.base = vm->gdt;
        sregs.gdt.limit = getpagesize() - 1;
        kvm_seg_set_kernel_data_64bit(NULL, DEFAULT_DATA_SELECTOR, &sregs.gs);
        vcpu_sregs_set(vm, vcpuid, &sregs);
        *(vm_vaddr_t *)addr_gva2hva(vm, (vm_vaddr_t)(&exception_handlers)) = vm->handlers;
}

void vm_install_exception_handler(struct kvm_vm *vm, int vector,
                               void (*handler)(struct ex_regs *))
{
        vm_vaddr_t *handlers = (vm_vaddr_t *)addr_gva2hva(vm, vm->handlers);

        handlers[vector] = (vm_vaddr_t)handler;
}

void assert_on_unhandled_exception(struct kvm_vm *vm, uint32_t vcpuid)
{
        struct ucall uc;

        if (get_ucall(vm, vcpuid, &uc) == UCALL_UNHANDLED) {
                uint64_t vector = uc.args[0];

                TEST_FAIL("Unexpected vectored event in guest (vector:0x%lx)",
                          vector);
        }
}

bool set_cpuid(struct kvm_cpuid2 *cpuid,
               struct kvm_cpuid_entry2 *ent)
{
        int i;

        for (i = 0; i < cpuid->nent; i++) {
                struct kvm_cpuid_entry2 *cur = &cpuid->entries[i];

                if (cur->function != ent->function || cur->index != ent->index)
                        continue;

                memcpy(cur, ent, sizeof(struct kvm_cpuid_entry2));
                return true;
        }

        return false;
}

uint64_t kvm_hypercall(uint64_t nr, uint64_t a0, uint64_t a1, uint64_t a2,
                       uint64_t a3)
{
        uint64_t r;

        asm volatile("vmcall"
                     : "=a"(r)
                     : "b"(a0), "c"(a1), "d"(a2), "S"(a3));
        return r;
}

struct kvm_cpuid2 *kvm_get_supported_hv_cpuid(void)
{
        static struct kvm_cpuid2 *cpuid;
        int ret;
        int kvm_fd;

        if (cpuid)
                return cpuid;

        cpuid = allocate_kvm_cpuid2();
        kvm_fd = open_kvm_dev_path_or_exit();

        ret = ioctl(kvm_fd, KVM_GET_SUPPORTED_HV_CPUID, cpuid);
        TEST_ASSERT(ret == 0, "KVM_GET_SUPPORTED_HV_CPUID failed %d %d\n",
                    ret, errno);

        close(kvm_fd);
        return cpuid;
}

void vcpu_set_hv_cpuid(struct kvm_vm *vm, uint32_t vcpuid)
{
        static struct kvm_cpuid2 *cpuid_full;
        struct kvm_cpuid2 *cpuid_sys, *cpuid_hv;
        int i, nent = 0;

        if (!cpuid_full) {
                cpuid_sys = kvm_get_supported_cpuid();
                cpuid_hv = kvm_get_supported_hv_cpuid();

                cpuid_full = malloc(sizeof(*cpuid_full) +
                                    (cpuid_sys->nent + cpuid_hv->nent) *
                                    sizeof(struct kvm_cpuid_entry2));
                if (!cpuid_full) {
                        perror("malloc");
                        abort();
                }

                /* Need to skip KVM CPUID leaves 0x400000xx */
                for (i = 0; i < cpuid_sys->nent; i++) {
                        if (cpuid_sys->entries[i].function >= 0x40000000 &&
                            cpuid_sys->entries[i].function < 0x40000100)
                                continue;
                        cpuid_full->entries[nent] = cpuid_sys->entries[i];
                        nent++;
                }

                memcpy(&cpuid_full->entries[nent], cpuid_hv->entries,
                       cpuid_hv->nent * sizeof(struct kvm_cpuid_entry2));
                cpuid_full->nent = nent + cpuid_hv->nent;
        }

        vcpu_set_cpuid(vm, vcpuid, cpuid_full);
}

struct kvm_cpuid2 *vcpu_get_supported_hv_cpuid(struct kvm_vm *vm, uint32_t vcpuid)
{
        static struct kvm_cpuid2 *cpuid;

        cpuid = allocate_kvm_cpuid2();

        vcpu_ioctl(vm, vcpuid, KVM_GET_SUPPORTED_HV_CPUID, cpuid);

        return cpuid;
}

#define X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx 0x68747541
#define X86EMUL_CPUID_VENDOR_AuthenticAMD_ecx 0x444d4163
#define X86EMUL_CPUID_VENDOR_AuthenticAMD_edx 0x69746e65

static inline unsigned x86_family(unsigned int eax)
{
        unsigned int x86;

        x86 = (eax >> 8) & 0xf;

        if (x86 == 0xf)
                x86 += (eax >> 20) & 0xff;

        return x86;
}

unsigned long vm_compute_max_gfn(struct kvm_vm *vm)
{
        const unsigned long num_ht_pages = 12 << (30 - vm->page_shift); /* 12 GiB */
        unsigned long ht_gfn, max_gfn, max_pfn;
        uint32_t eax, ebx, ecx, edx, max_ext_leaf;

        max_gfn = (1ULL << (vm->pa_bits - vm->page_shift)) - 1;

        /* Avoid reserved HyperTransport region on AMD processors.  */
        eax = ecx = 0;
        cpuid(&eax, &ebx, &ecx, &edx);
        if (ebx != X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx ||
            ecx != X86EMUL_CPUID_VENDOR_AuthenticAMD_ecx ||
            edx != X86EMUL_CPUID_VENDOR_AuthenticAMD_edx)
                return max_gfn;

        /* On parts with <40 physical address bits, the area is fully hidden */
        if (vm->pa_bits < 40)
                return max_gfn;

        /* Before family 17h, the HyperTransport area is just below 1T.  */
        ht_gfn = (1 << 28) - num_ht_pages;
        eax = 1;
        cpuid(&eax, &ebx, &ecx, &edx);
        if (x86_family(eax) < 0x17)
                goto done;

        /*
         * Otherwise it's at the top of the physical address space, possibly
         * reduced due to SME by bits 11:6 of CPUID[0x8000001f].EBX.  Use
         * the old conservative value if MAXPHYADDR is not enumerated.
         */
        eax = 0x80000000;
        cpuid(&eax, &ebx, &ecx, &edx);
        max_ext_leaf = eax;
        if (max_ext_leaf < 0x80000008)
                goto done;

        eax = 0x80000008;
        cpuid(&eax, &ebx, &ecx, &edx);
        max_pfn = (1ULL << ((eax & 0xff) - vm->page_shift)) - 1;
        if (max_ext_leaf >= 0x8000001f) {
                eax = 0x8000001f;
                cpuid(&eax, &ebx, &ecx, &edx);
                max_pfn >>= (ebx >> 6) & 0x3f;
        }

        ht_gfn = max_pfn - num_ht_pages;
done:
        return min(max_gfn, ht_gfn - 1);
}