diff mbox series

[5.4,3/3] KVM: x86: Make use of kvm_read_cr*_bits() when testing bits

Message ID 20230508154943.30113-4-minipli@grsecurity.net (mailing list archive)
State New, archived
Headers show
Series KVM CR0.WP series backport | expand

Commit Message

Mathias Krause May 8, 2023, 3:49 p.m. UTC 
[ Upstream commit 74cdc836919bf34684ef66f995273f35e2189daf ]

Make use of the kvm_read_cr{0,4}_bits() helper functions when we only
want to know the state of certain bits instead of the whole register.

This not only makes the intent cleaner, it also avoids a potential
VMREAD in case the tested bits aren't guest owned.

Signed-off-by: Mathias Krause <minipli@grsecurity.net>
Link: https://lore.kernel.org/r/20230322013731.102955-5-minipli@grsecurity.net
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Mathias Krause <minipli@grsecurity.net>	# backport to 5.4.x
---
 arch/x86/kvm/vmx/vmx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index e6dd6a7e8689..9bbbb201bab5 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4970,7 +4970,7 @@  static int handle_cr(struct kvm_vcpu *vcpu)
 		break;
 	case 3: /* lmsw */
 		val = (exit_qualification >> LMSW_SOURCE_DATA_SHIFT) & 0x0f;
-		trace_kvm_cr_write(0, (kvm_read_cr0(vcpu) & ~0xful) | val);
+		trace_kvm_cr_write(0, (kvm_read_cr0_bits(vcpu, ~0xful) | val));
 		kvm_lmsw(vcpu, val);
 
 		return kvm_skip_emulated_instruction(vcpu);
@@ -6982,7 +6982,7 @@  static u64 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
 		goto exit;
 	}
 
-	if (kvm_read_cr0(vcpu) & X86_CR0_CD) {
+	if (kvm_read_cr0_bits(vcpu, X86_CR0_CD)) {
 		ipat = VMX_EPT_IPAT_BIT;
 		if (kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_CD_NW_CLEARED))
 			cache = MTRR_TYPE_WRBACK;