From: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Upstream commit bf03d4f9334728bf7c8ffc7de787df48abd6340e.
Checking for 32-bit PAE is quite common around code that fiddles with
the PDPTRs. Add a function to compress all checks into a single
invocation.
Moving to the common helper also fixes a subtle bug in kvm_set_cr3()
where it fails to check is_long_mode() and results in KVM incorrectly
attempting to load PDPTRs for a 64-bit guest.
Reviewed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
[sean: backport to 4.x; handle vmx.c split in 5.x, call out the bugfix]
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
arch/x86/kvm/vmx.c | 7 +++----
arch/x86/kvm/x86.c | 8 ++++----
arch/x86/kvm/x86.h | 5 +++++
3 files changed, 12 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 6f7b3acdab26..83acaed244ba 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5181,7 +5181,7 @@ static void ept_load_pdptrs(struct kvm_vcpu *vcpu)
(unsigned long *)&vcpu->arch.regs_dirty))
return;
- if (is_paging(vcpu) && is_pae(vcpu) && !is_long_mode(vcpu)) {
+ if (is_pae_paging(vcpu)) {
vmcs_write64(GUEST_PDPTR0, mmu->pdptrs[0]);
vmcs_write64(GUEST_PDPTR1, mmu->pdptrs[1]);
vmcs_write64(GUEST_PDPTR2, mmu->pdptrs[2]);
@@ -5193,7 +5193,7 @@ static void ept_save_pdptrs(struct kvm_vcpu *vcpu)
{
struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
- if (is_paging(vcpu) && is_pae(vcpu) && !is_long_mode(vcpu)) {
+ if (is_pae_paging(vcpu)) {
mmu->pdptrs[0] = vmcs_read64(GUEST_PDPTR0);
mmu->pdptrs[1] = vmcs_read64(GUEST_PDPTR1);
mmu->pdptrs[2] = vmcs_read64(GUEST_PDPTR2);
@@ -12021,8 +12021,7 @@ static int nested_vmx_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3, bool ne
* If PAE paging and EPT are both on, CR3 is not used by the CPU and
* must not be dereferenced.
*/
- if (!is_long_mode(vcpu) && is_pae(vcpu) && is_paging(vcpu) &&
- !nested_ept) {
+ if (is_pae_paging(vcpu) && !nested_ept) {
if (!load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3)) {
*entry_failure_code = ENTRY_FAIL_PDPTE;
return 1;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6ae8a013af31..b9b87fb75ac0 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -633,7 +633,7 @@ bool pdptrs_changed(struct kvm_vcpu *vcpu)
gfn_t gfn;
int r;
- if (is_long_mode(vcpu) || !is_pae(vcpu) || !is_paging(vcpu))
+ if (!is_pae_paging(vcpu))
return false;
if (!test_bit(VCPU_EXREG_PDPTR,
@@ -884,8 +884,8 @@ int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
if (is_long_mode(vcpu) &&
(cr3 & rsvd_bits(cpuid_maxphyaddr(vcpu), 63)))
return 1;
- else if (is_pae(vcpu) && is_paging(vcpu) &&
- !load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3))
+ else if (is_pae_paging(vcpu) &&
+ !load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3))
return 1;
kvm_mmu_new_cr3(vcpu, cr3, skip_tlb_flush);
@@ -8312,7 +8312,7 @@ static int __set_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
kvm_update_cpuid(vcpu);
idx = srcu_read_lock(&vcpu->kvm->srcu);
- if (!is_long_mode(vcpu) && is_pae(vcpu) && is_paging(vcpu)) {
+ if (is_pae_paging(vcpu)) {
load_pdptrs(vcpu, vcpu->arch.walk_mmu, kvm_read_cr3(vcpu));
mmu_reset_needed = 1;
}
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 3a91ea760f07..608e5f8c5d0a 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -139,6 +139,11 @@ static inline int is_paging(struct kvm_vcpu *vcpu)
return likely(kvm_read_cr0_bits(vcpu, X86_CR0_PG));
}
+static inline bool is_pae_paging(struct kvm_vcpu *vcpu)
+{
+ return !is_long_mode(vcpu) && is_pae(vcpu) && is_paging(vcpu);
+}
+
static inline u32 bit(int bitno)
{
return 1 << (bitno & 31);
--
2.24.0
