[PATCH 5.19 083/155] KVM: VMX: Heed the msr argument in msr_write_intercepted()

Greg Kroah-Hartman
2022-09-06T14:11:54Z

From: Jim Mattson <jmattson@google.com>

[ Upstream commit 020dac4187968535f089f83f376a72beb3451311 ]

Regardless of the 'msr' argument passed to the VMX version of
msr_write_intercepted(), the function always checks to see if a
specific MSR (IA32_SPEC_CTRL) is intercepted for write. This behavior
seems unintentional and unexpected.

Modify the function so that it checks to see if the provided 'msr'
index is intercepted for write.

Fixes: 67f4b9969c30 ("KVM: nVMX: Handle dynamic MSR intercept toggling")
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220810213050.2655000-1-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/kvm/vmx/vmx.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 0aaea87a14597..b09a50e0af29d 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -835,8 +835,7 @@ static bool msr_write_intercepted(struct vcpu_vmx *vmx, u32 msr)
if (!(exec_controls_get(vmx) & CPU_BASED_USE_MSR_BITMAPS))
return true;

- return vmx_test_msr_bitmap_write(vmx->loaded_vmcs->msr_bitmap,
- MSR_IA32_SPEC_CTRL);
+ return vmx_test_msr_bitmap_write(vmx->loaded_vmcs->msr_bitmap, msr);
}

unsigned int __vmx_vcpu_run_flags(struct vcpu_vmx *vmx)
--
2.35.1