[1/4,v3,nVMX] : Check "load IA32_PAT" VM-exit control on vmentry
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Message ID 20190403215905.2474-2-krish.sadhukhan@oracle.com
State New
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  • [1/4,v3,nVMX] : Check "load IA32_PAT" VM-exit control on vmentry
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Commit Message

Krish Sadhukhan April 3, 2019, 9:59 p.m. UTC
According to section "Checks on Host Control Registers and MSRs" in Intel
SDM vol 3C, the following check is performed on vmentry:

    If the "load IA32_PAT" VM-exit control is 1, the value of the field
    for the IA32_PAT MSR must be one that could be written by WRMSR
    without fault at CPL 0. Specifically, each of the 8 bytes in the
    field must have one of the values 0 (UC), 1 (WC), 4 (WT), 5 (WP),
    6 (WB), or 7 (UC-).

Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Karl Heubaum <karl.heubaum@oracle.com>
Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/nested.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Jim Mattson April 4, 2019, 5:28 p.m. UTC | #1
On Wed, Apr 3, 2019 at 3:27 PM Krish Sadhukhan
<krish.sadhukhan@oracle.com> wrote:
>
> According to section "Checks on Host Control Registers and MSRs" in Intel
> SDM vol 3C, the following check is performed on vmentry:
>
>     If the "load IA32_PAT" VM-exit control is 1, the value of the field
>     for the IA32_PAT MSR must be one that could be written by WRMSR
>     without fault at CPL 0. Specifically, each of the 8 bytes in the
>     field must have one of the values 0 (UC), 1 (WC), 4 (WT), 5 (WP),
>     6 (WB), or 7 (UC-).
>
> Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
> Reviewed-by: Karl Heubaum <karl.heubaum@oracle.com>
> Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Jim Mattson <jmattson@google.com>

Patch
diff mbox series

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 3170e291215d..f601b156ca84 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2595,6 +2595,11 @@  static int nested_check_host_control_regs(struct kvm_vcpu *vcpu,
 	    !nested_host_cr4_valid(vcpu, vmcs12->host_cr4) ||
 	    !nested_cr3_valid(vcpu, vmcs12->host_cr3))
 		return -EINVAL;
+
+	if ((vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PAT) &&
+	    !kvm_mtrr_valid(vcpu, MSR_IA32_CR_PAT, vmcs12->host_ia32_pat))
+			return -EINVAL;
+
 	/*
 	 * If the load IA32_EFER VM-exit control is 1, bits reserved in the
 	 * IA32_EFER MSR must be 0 in the field for that register. In addition,