Commit 52ce3c21 authored Oct 07, 2014 by Andy Lutomirski Committed by Paolo Bonzini Nov 03, 2014

x86,kvm,vmx: Don't trap writes to CR4.TSD



CR4.TSD is guest-owned; don't trap writes to it in VMX guests.  This
avoids a VM exit on context switches into or out of a PR_TSC_SIGSEGV
task.

I think that this fixes an unintentional side-effect of:
    4c38609a KVM: VMX: Make guest cr4 mask more conservative

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent bf0b682c

arch/x86/kvm/vmx.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -105,7 +105,7 @@ module_param(nested, bool, S_IRUGO);
		(KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST \| X86_CR0_PG \| X86_CR0_PE)
		#define KVM_CR4_GUEST_OWNED_BITS \
		(X86_CR4_PVI \| X86_CR4_DE \| X86_CR4_PCE \| X86_CR4_OSFXSR \
		\| X86_CR4_OSXMMEXCPT)
		\| X86_CR4_OSXMMEXCPT \| X86_CR4_TSD)

		#define KVM_PMODE_VM_CR4_ALWAYS_ON (X86_CR4_PAE \| X86_CR4_VMXE)
		#define KVM_RMODE_VM_CR4_ALWAYS_ON (X86_CR4_VME \| X86_CR4_PAE \| X86_CR4_VMXE)