diff options
author | Sean Christopherson <seanjc@google.com> | 2021-07-13 09:33:05 -0700 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-08-02 11:01:55 -0400 |
commit | 32437c2aea428f9c3479904e342b02f5eee3a7f6 (patch) | |
tree | 1ca275ef09566232864107634cdc2491196cb3f7 | |
parent | KVM: x86/mmu: Skip the permission_fault() check on MMIO if CR0.PG=0 (diff) | |
download | linux-32437c2aea428f9c3479904e342b02f5eee3a7f6.tar.gz linux-32437c2aea428f9c3479904e342b02f5eee3a7f6.tar.bz2 linux-32437c2aea428f9c3479904e342b02f5eee3a7f6.zip |
KVM: VMX: Process CR0.PG side effects after setting CR0 assets
Move the long mode and EPT w/o unrestricted guest side effect processing
down in vmx_set_cr0() so that the EPT && !URG case doesn't have to stuff
vcpu->arch.cr0 early. This also fixes an oddity where CR0 might not be
marked available, i.e. the early vcpu->arch.cr0 write would appear to be
in danger of being overwritten, though that can't actually happen in the
current code since CR0.TS is the only guest-owned bit, and CR0.TS is not
read by vmx_set_cr4().
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210713163324.627647-28-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 0c1e578967ff..aa547100f0df 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -3003,9 +3003,11 @@ void ept_save_pdptrs(struct kvm_vcpu *vcpu) void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) { struct vcpu_vmx *vmx = to_vmx(vcpu); - unsigned long hw_cr0; + unsigned long hw_cr0, old_cr0_pg; u32 tmp; + old_cr0_pg = kvm_read_cr0_bits(vcpu, X86_CR0_PG); + hw_cr0 = (cr0 & ~KVM_VM_CR0_ALWAYS_OFF); if (is_unrestricted_guest(vcpu)) hw_cr0 |= KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST; @@ -3021,11 +3023,16 @@ void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) enter_rmode(vcpu); } + vmcs_writel(CR0_READ_SHADOW, cr0); + vmcs_writel(GUEST_CR0, hw_cr0); + vcpu->arch.cr0 = cr0; + kvm_register_mark_available(vcpu, VCPU_EXREG_CR0); + #ifdef CONFIG_X86_64 if (vcpu->arch.efer & EFER_LME) { - if (!is_paging(vcpu) && (cr0 & X86_CR0_PG)) + if (!old_cr0_pg && (cr0 & X86_CR0_PG)) enter_lmode(vcpu); - if (is_paging(vcpu) && !(cr0 & X86_CR0_PG)) + else if (old_cr0_pg && !(cr0 & X86_CR0_PG)) exit_lmode(vcpu); } #endif @@ -3066,17 +3073,11 @@ void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) exec_controls_set(vmx, tmp); } - if (!is_paging(vcpu) != !(cr0 & X86_CR0_PG)) { - vcpu->arch.cr0 = cr0; + /* Note, vmx_set_cr4() consumes the new vcpu->arch.cr0. */ + if ((old_cr0_pg ^ cr0) & X86_CR0_PG) vmx_set_cr4(vcpu, kvm_read_cr4(vcpu)); - } } - vmcs_writel(CR0_READ_SHADOW, cr0); - vmcs_writel(GUEST_CR0, hw_cr0); - vcpu->arch.cr0 = cr0; - kvm_register_mark_available(vcpu, VCPU_EXREG_CR0); - /* depends on vcpu->arch.cr0 to be set to a new value */ vmx->emulation_required = emulation_required(vcpu); } |