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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* HVM domain specific functions.
*
* Copyright (C) 2017 Citrix Systems R&D
*/
#include <xen/domain_page.h>
#include <xen/errno.h>
#include <xen/lib.h>
#include <xen/paging.h>
#include <xen/sched.h>
#include <asm/hvm/emulate.h>
#include <public/hvm/hvm_vcpu.h>
static int check_segment(struct segment_register *reg, enum x86_segment seg)
{
if ( reg->pad != 0 )
{
gprintk(XENLOG_ERR, "Segment attribute bits 12-15 are not zero\n");
return -EINVAL;
}
if ( reg->attr == 0 )
{
if ( seg != x86_seg_ds && seg != x86_seg_es )
{
gprintk(XENLOG_ERR, "Null segment attributes for CS, SS or TR\n");
return -EINVAL;
}
return 0;
}
if ( seg == x86_seg_tr )
{
if ( reg->s )
{
gprintk(XENLOG_ERR, "Code or data segment provided for TR\n");
return -EINVAL;
}
if ( reg->type != SYS_DESC_tss_busy )
{
gprintk(XENLOG_ERR, "Non-32-bit-TSS segment provided for TR\n");
return -EINVAL;
}
}
else if ( !reg->s )
{
gprintk(XENLOG_ERR,
"System segment provided for a code or data segment\n");
return -EINVAL;
}
if ( !reg->p )
{
gprintk(XENLOG_ERR, "Non-present segment provided\n");
return -EINVAL;
}
switch ( seg )
{
case x86_seg_cs:
if ( !(reg->type & 0x8) )
{
gprintk(XENLOG_ERR, "Non-code segment provided for CS\n");
return -EINVAL;
}
break;
case x86_seg_ss:
if ( (reg->type & 0x8) || !(reg->type & 0x2) )
{
gprintk(XENLOG_ERR, "Non-writeable segment provided for SS\n");
return -EINVAL;
}
break;
case x86_seg_ds:
case x86_seg_es:
if ( (reg->type & 0x8) && !(reg->type & 0x2) )
{
gprintk(XENLOG_ERR, "Non-readable segment provided for DS or ES\n");
return -EINVAL;
}
break;
case x86_seg_tr:
break;
default:
ASSERT_UNREACHABLE();
return -EINVAL;
}
return 0;
}
/* Called by VCPUOP_initialise for HVM guests. */
int arch_set_info_hvm_guest(struct vcpu *v, const vcpu_hvm_context_t *ctx)
{
const struct domain *d = v->domain;
struct cpu_user_regs *uregs = &v->arch.user_regs;
struct segment_register cs, ds, ss, es, tr;
const char *errstr;
int rc;
if ( ctx->pad != 0 )
return -EINVAL;
switch ( ctx->mode )
{
default:
return -EINVAL;
case VCPU_HVM_MODE_32B:
{
const struct vcpu_hvm_x86_32 *regs = &ctx->cpu_regs.x86_32;
uint32_t limit;
if ( ctx->cpu_regs.x86_32.pad1 != 0 ||
ctx->cpu_regs.x86_32.pad2[0] != 0 ||
ctx->cpu_regs.x86_32.pad2[1] != 0 ||
ctx->cpu_regs.x86_32.pad2[2] != 0 )
return -EINVAL;
#define SEG(s, r) ({ \
s = (struct segment_register) \
{ 0, { (r)->s ## _ar }, (r)->s ## _limit, (r)->s ## _base }; \
/* Set accessed / busy bit for present segments. */ \
if ( s.p ) \
s.type |= (x86_seg_##s != x86_seg_tr ? 1 : 2); \
check_segment(&s, x86_seg_ ## s); })
rc = SEG(cs, regs);
rc |= SEG(ds, regs);
rc |= SEG(ss, regs);
rc |= SEG(es, regs);
rc |= SEG(tr, regs);
#undef SEG
if ( rc != 0 )
return rc;
/* Basic sanity checks. */
limit = cs.limit;
if ( cs.g )
limit = (limit << 12) | 0xfff;
if ( regs->eip > limit )
{
gprintk(XENLOG_ERR, "EIP (%#08x) outside CS limit (%#08x)\n",
regs->eip, limit);
return -EINVAL;
}
if ( ss.dpl != cs.dpl )
{
gprintk(XENLOG_ERR, "SS.DPL (%u) is different than CS.DPL (%u)\n",
ss.dpl, cs.dpl);
return -EINVAL;
}
if ( ds.p && ds.dpl > cs.dpl )
{
gprintk(XENLOG_ERR, "DS.DPL (%u) is greater than CS.DPL (%u)\n",
ds.dpl, cs.dpl);
return -EINVAL;
}
if ( es.p && es.dpl > cs.dpl )
{
gprintk(XENLOG_ERR, "ES.DPL (%u) is greater than CS.DPL (%u)\n",
es.dpl, cs.dpl);
return -EINVAL;
}
if ( (regs->efer & EFER_LMA) && !(regs->efer & EFER_LME) )
{
gprintk(XENLOG_ERR, "EFER.LMA set without EFER.LME (%#016lx)\n",
regs->efer);
return -EINVAL;
}
uregs->rax = regs->eax;
uregs->rcx = regs->ecx;
uregs->rdx = regs->edx;
uregs->rbx = regs->ebx;
uregs->rsp = regs->esp;
uregs->rbp = regs->ebp;
uregs->rsi = regs->esi;
uregs->rdi = regs->edi;
uregs->rip = regs->eip;
uregs->rflags = regs->eflags;
v->arch.hvm.guest_cr[0] = regs->cr0;
v->arch.hvm.guest_cr[3] = regs->cr3;
v->arch.hvm.guest_cr[4] = regs->cr4;
v->arch.hvm.guest_efer = regs->efer;
}
break;
case VCPU_HVM_MODE_64B:
{
const struct vcpu_hvm_x86_64 *regs = &ctx->cpu_regs.x86_64;
/* Basic sanity checks. */
if ( !is_canonical_address(regs->rip) )
{
gprintk(XENLOG_ERR, "RIP contains a non-canonical address (%#lx)\n",
regs->rip);
return -EINVAL;
}
if ( !(regs->cr0 & X86_CR0_PG) )
{
gprintk(XENLOG_ERR, "CR0 doesn't have paging enabled (%#016lx)\n",
regs->cr0);
return -EINVAL;
}
if ( !(regs->cr4 & X86_CR4_PAE) )
{
gprintk(XENLOG_ERR, "CR4 doesn't have PAE enabled (%#016lx)\n",
regs->cr4);
return -EINVAL;
}
if ( !(regs->efer & EFER_LME) )
{
gprintk(XENLOG_ERR, "EFER doesn't have LME enabled (%#016lx)\n",
regs->efer);
return -EINVAL;
}
uregs->rax = regs->rax;
uregs->rcx = regs->rcx;
uregs->rdx = regs->rdx;
uregs->rbx = regs->rbx;
uregs->rsp = regs->rsp;
uregs->rbp = regs->rbp;
uregs->rsi = regs->rsi;
uregs->rdi = regs->rdi;
uregs->rip = regs->rip;
uregs->rflags = regs->rflags;
v->arch.hvm.guest_cr[0] = regs->cr0;
v->arch.hvm.guest_cr[3] = regs->cr3;
v->arch.hvm.guest_cr[4] = regs->cr4;
v->arch.hvm.guest_efer = regs->efer;
#define SEG(l, a) (struct segment_register){ 0, { a }, l, 0 }
cs = SEG(~0u, 0xa9b); /* 64bit code segment. */
ds = ss = es = SEG(~0u, 0xc93);
tr = SEG(0x67, 0x8b); /* 64bit TSS (busy). */
#undef SEG
}
break;
}
if ( v->arch.hvm.guest_efer & EFER_LME )
v->arch.hvm.guest_efer |= EFER_LMA;
if ( v->arch.hvm.guest_cr[4] & ~hvm_cr4_guest_valid_bits(d) )
{
gprintk(XENLOG_ERR, "Bad CR4 value: %#016lx\n",
v->arch.hvm.guest_cr[4]);
return -EINVAL;
}
errstr = hvm_efer_valid(v, v->arch.hvm.guest_efer, -1);
if ( errstr )
{
gprintk(XENLOG_ERR, "Bad EFER value (%#016lx): %s\n",
v->arch.hvm.guest_efer, errstr);
return -EINVAL;
}
hvm_update_guest_cr(v, 0);
hvm_update_guest_cr(v, 3);
hvm_update_guest_cr(v, 4);
hvm_update_guest_efer(v);
if ( hvm_paging_enabled(v) && !paging_mode_hap(v->domain) )
{
/* Shadow-mode CR3 change. Check PDBR and update refcounts. */
struct page_info *page = get_page_from_gfn(v->domain,
v->arch.hvm.guest_cr[3] >> PAGE_SHIFT,
NULL, P2M_ALLOC);
if ( !page )
{
gprintk(XENLOG_ERR, "Invalid CR3: %#lx\n",
v->arch.hvm.guest_cr[3]);
return -EINVAL;
}
v->arch.guest_table = pagetable_from_page(page);
}
hvm_set_segment_register(v, x86_seg_cs, &cs);
hvm_set_segment_register(v, x86_seg_ds, &ds);
hvm_set_segment_register(v, x86_seg_ss, &ss);
hvm_set_segment_register(v, x86_seg_es, &es);
hvm_set_segment_register(v, x86_seg_tr, &tr);
/* Sync AP's TSC with BSP's. */
v->arch.hvm.cache_tsc_offset =
d->vcpu[0]->arch.hvm.cache_tsc_offset;
hvm_set_tsc_offset(v, v->arch.hvm.cache_tsc_offset,
d->arch.hvm.sync_tsc);
paging_update_paging_modes(v);
hvmemul_cancel(v);
v->is_initialised = 1;
set_bit(_VPF_down, &v->pause_flags);
return 0;
}
/*
* Local variables:
* mode: C
* c-file-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/
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