KVM: VMX: Invert handling of CR0.WP for EPT without unrestricted guest

Opt-in to forcing CR0.WP=1 for shadow paging, and stop lying about WP
being "always on" for unrestricted guest.  In addition to making KVM a
wee bit more honest, this paves the way for additional cleanup.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210713163324.627647-22-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson 2021-07-13 09:32:59 -07:00 committed by Paolo Bonzini
parent 9e90e215d9
commit ee5a5584cb

View File

@ -136,8 +136,7 @@ module_param(allow_smaller_maxphyaddr, bool, S_IRUGO);
#define KVM_VM_CR0_ALWAYS_OFF (X86_CR0_NW | X86_CR0_CD)
#define KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST X86_CR0_NE
#define KVM_VM_CR0_ALWAYS_ON \
(KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST | \
X86_CR0_WP | X86_CR0_PG | X86_CR0_PE)
(KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST | X86_CR0_PG | X86_CR0_PE)
#define KVM_VM_CR4_ALWAYS_ON_UNRESTRICTED_GUEST X86_CR4_VMXE
#define KVM_PMODE_VM_CR4_ALWAYS_ON (X86_CR4_PAE | X86_CR4_VMXE)
@ -2995,9 +2994,7 @@ void ept_save_pdptrs(struct kvm_vcpu *vcpu)
kvm_register_mark_dirty(vcpu, VCPU_EXREG_PDPTR);
}
static void ept_update_paging_mode_cr0(unsigned long *hw_cr0,
unsigned long cr0,
struct kvm_vcpu *vcpu)
static void ept_update_paging_mode_cr0(unsigned long cr0, struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
@ -3016,9 +3013,6 @@ static void ept_update_paging_mode_cr0(unsigned long *hw_cr0,
vcpu->arch.cr0 = cr0;
vmx_set_cr4(vcpu, kvm_read_cr4(vcpu));
}
if (!(cr0 & X86_CR0_WP))
*hw_cr0 &= ~X86_CR0_WP;
}
void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
@ -3031,6 +3025,8 @@ void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
hw_cr0 |= KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST;
else {
hw_cr0 |= KVM_VM_CR0_ALWAYS_ON;
if (!enable_ept)
hw_cr0 |= X86_CR0_WP;
if (vmx->rmode.vm86_active && (cr0 & X86_CR0_PE))
enter_pmode(vcpu);
@ -3049,7 +3045,7 @@ void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
#endif
if (enable_ept && !is_unrestricted_guest(vcpu))
ept_update_paging_mode_cr0(&hw_cr0, cr0, vcpu);
ept_update_paging_mode_cr0(cr0, vcpu);
vmcs_writel(CR0_READ_SHADOW, cr0);
vmcs_writel(GUEST_CR0, hw_cr0);