| From a8b6fda38f80e75afa3b125c9e7f2550b579454b Mon Sep 17 00:00:00 2001 |
| From: Jim Mattson <jmattson@google.com> |
| Date: Tue, 23 May 2017 11:52:52 -0700 |
| Subject: kvm: vmx: Do not disable intercepts for BNDCFGS |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| From: Jim Mattson <jmattson@google.com> |
| |
| commit a8b6fda38f80e75afa3b125c9e7f2550b579454b upstream. |
| |
| The MSR permission bitmaps are shared by all VMs. However, some VMs |
| may not be configured to support MPX, even when the host does. If the |
| host supports VMX and the guest does not, we should intercept accesses |
| to the BNDCFGS MSR, so that we can synthesize a #GP |
| fault. Furthermore, if the host does not support MPX and the |
| "ignore_msrs" kvm kernel parameter is set, then we should intercept |
| accesses to the BNDCFGS MSR, so that we can skip over the rdmsr/wrmsr |
| without raising a #GP fault. |
| |
| Fixes: da8999d31818fdc8 ("KVM: x86: Intel MPX vmx and msr handle") |
| Signed-off-by: Jim Mattson <jmattson@google.com> |
| Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| arch/x86/kvm/vmx.c | 1 - |
| 1 file changed, 1 deletion(-) |
| |
| --- a/arch/x86/kvm/vmx.c |
| +++ b/arch/x86/kvm/vmx.c |
| @@ -6474,7 +6474,6 @@ static __init int hardware_setup(void) |
| vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_CS, false); |
| vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_ESP, false); |
| vmx_disable_intercept_for_msr(MSR_IA32_SYSENTER_EIP, false); |
| - vmx_disable_intercept_for_msr(MSR_IA32_BNDCFGS, true); |
| |
| memcpy(vmx_msr_bitmap_legacy_x2apic, |
| vmx_msr_bitmap_legacy, PAGE_SIZE); |
