From 4ff417320c2dfc984ec1939a7da888976441a881 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 24 Feb 2014 12:15:16 +0100 Subject: KVM: x86: introduce kvm_supported_xcr0() XSAVE support for KVM is already using host_xcr0 & KVM_SUPPORTED_XCR0 as a "dynamic" version of KVM_SUPPORTED_XCR0. However, this is not enough because the MPX bits should not be presented to the guest unless kvm_x86_ops confirms the support. So, replace all instances of host_xcr0 & KVM_SUPPORTED_XCR0 with a new function kvm_supported_xcr0() that also has this check. Note that here: if (xstate_bv & ~KVM_SUPPORTED_XCR0) return -EINVAL; if (xstate_bv & ~host_cr0) return -EINVAL; the code is equivalent to if ((xstate_bv & ~KVM_SUPPORTED_XCR0) || (xstate_bv & ~host_cr0) return -EINVAL; i.e. "xstate_bv & (~KVM_SUPPORTED_XCR0 | ~host_cr0)" which is in turn equal to "xstate_bv & ~(KVM_SUPPORTED_XCR0 & host_cr0)". So we should also use the new function there. Signed-off-by: Paolo Bonzini --- arch/x86/kvm/x86.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/kvm/x86.h') diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index 392ecbff0030..8c97bac9a895 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -126,6 +126,8 @@ int kvm_write_guest_virt_system(struct x86_emulate_ctxt *ctxt, | XSTATE_BNDREGS | XSTATE_BNDCSR) extern u64 host_xcr0; +extern u64 kvm_supported_xcr0(void); + extern unsigned int min_timer_period_us; extern struct static_key kvm_no_apic_vcpu; -- cgit v1.2.3