This is a note to let you know that I've just added the patch titled
KVM: VMX: Invert handling of CR0.WP for EPT without unrestricted guest
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-vmx-invert-handling-of-cr0.wp-for-ept-without-un.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2faba2d4314b6a745f1c103aef2342cce630c813
Author: Sean Christopherson <seanjc@xxxxxxxxxx>
Date: Tue Jul 13 09:32:59 2021 -0700
KVM: VMX: Invert handling of CR0.WP for EPT without unrestricted guest
[ Upstream commit ee5a5584cba316bc90bc2fad0c6d10b71f1791cb ]
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@xxxxxxxxxx>
Message-Id: <20210713163324.627647-22-seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Stable-dep-of: c4abd7352023 ("KVM: VMX: Don't fudge CR0 and CR4 for restricted L2 guest")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 9aedc7b06da7a..574acfa98fa9b 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -135,8 +135,7 @@ 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)
@@ -3064,9 +3063,7 @@ 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);
@@ -3085,9 +3082,6 @@ 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)
@@ -3100,6 +3094,8 @@ 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);
@@ -3118,7 +3114,7 @@ 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);
