Patch "kvm: vmx: Do not disable intercepts for BNDCFGS" has been added to the 4.12-stable tree
Subsystems (3)
This is a note to let you know that I've just added the patch titled
kvm: vmx: Do not disable intercepts for BNDCFGS
to the 4.12-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-do-not-disable-intercepts-for-bndcfgs.patch
and it can be found in the queue-4.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.
Quoted 1 line
From
a8b6fda38f80e75afa3b125c9e7f2550b579454bMon Sep 17 00:00:00 2001
From: Jim Mattson <[email protected]>
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 <[email protected]>
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.
--- arch/x86/kvm/vmx.c | 1 - 1 file changed, 1 deletion(-)
arch/x86/kvm/vmx.c +0 -1
@@ -6547,7 +6547,6 @@ 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_apicv, vmx_msr_bitmap_legacy,PAGE_SIZE );
Patches currently in stable-queue which might be from [email protected] are
queue-4.12/kvm-x86-guest-bndcfgs-requires-guest-mpx-support.patch queue-4.12/kvm-vmx-check-value-written-to-ia32_bndcfgs.patch queue-4.12/kvm-vmx-do-not-disable-intercepts-for-bndcfgs.patch