KVM: x86: Fix CR3 reserved bits

According to Intel specifications, PAE and non-PAE does not have any reserved
bits.  In long-mode, regardless to PCIDE, only the high bits (above the
physical address) are reserved.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This commit is contained in:
Nadav Amit 2014-04-18 03:35:09 +03:00 committed by Marcelo Tosatti
parent 671bd9934a
commit 346874c950
3 changed files with 6 additions and 29 deletions

View File

@ -50,11 +50,7 @@
| X86_CR0_ET | X86_CR0_NE | X86_CR0_WP | X86_CR0_AM \
| X86_CR0_NW | X86_CR0_CD | X86_CR0_PG))
#define CR3_PAE_RESERVED_BITS ((X86_CR3_PWT | X86_CR3_PCD) - 1)
#define CR3_NONPAE_RESERVED_BITS ((PAGE_SIZE-1) & ~(X86_CR3_PWT | X86_CR3_PCD))
#define CR3_PCID_ENABLED_RESERVED_BITS 0xFFFFFF0000000000ULL
#define CR3_L_MODE_RESERVED_BITS (CR3_NONPAE_RESERVED_BITS | \
0xFFFFFF0000000000ULL)
#define CR3_L_MODE_RESERVED_BITS 0xFFFFFF0000000000ULL
#define CR4_RESERVED_BITS \
(~(unsigned long)(X86_CR4_VME | X86_CR4_PVI | X86_CR4_TSD | X86_CR4_DE\
| X86_CR4_PSE | X86_CR4_PAE | X86_CR4_MCE \

View File

@ -3388,10 +3388,6 @@ static int check_cr_write(struct x86_emulate_ctxt *ctxt)
ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
if (efer & EFER_LMA)
rsvd = CR3_L_MODE_RESERVED_BITS;
else if (ctxt->ops->get_cr(ctxt, 4) & X86_CR4_PAE)
rsvd = CR3_PAE_RESERVED_BITS;
else if (ctxt->ops->get_cr(ctxt, 0) & X86_CR0_PG)
rsvd = CR3_NONPAE_RESERVED_BITS;
if (new_val & rsvd)
return emulate_gp(ctxt, 0);

View File

@ -701,26 +701,11 @@ int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
return 0;
}
if (is_long_mode(vcpu)) {
if (kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE)) {
if (cr3 & CR3_PCID_ENABLED_RESERVED_BITS)
return 1;
} else
if (cr3 & CR3_L_MODE_RESERVED_BITS)
return 1;
} else {
if (is_pae(vcpu)) {
if (cr3 & CR3_PAE_RESERVED_BITS)
return 1;
if (is_paging(vcpu) &&
!load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3))
return 1;
}
/*
* We don't check reserved bits in nonpae mode, because
* this isn't enforced, and VMware depends on this.
*/
}
if (is_long_mode(vcpu) && (cr3 & CR3_L_MODE_RESERVED_BITS))
return 1;
if (is_pae(vcpu) && is_paging(vcpu) &&
!load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3))
return 1;
vcpu->arch.cr3 = cr3;
__set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);