From 5e520e62787afd8fc28626fd8d4f77491135119d Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Sun, 15 May 2011 10:13:12 -0400 Subject: KVM: VMX: Move VMREAD cleanup to exception handler We clean up a failed VMREAD by clearing the output register. Do it in the exception handler instead of unconditionally. This is worthwhile since there are more than a hundred call sites. Signed-off-by: Avi Kivity Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/vmx.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'arch/x86/kvm/vmx.c') diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index d48ec60ea421..7d22d6c6734d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -43,6 +43,8 @@ #include "trace.h" #define __ex(x) __kvm_handle_fault_on_reboot(x) +#define __ex_clear(x, reg) \ + ____kvm_handle_fault_on_reboot(x, "xor " reg " , " reg) MODULE_AUTHOR("Qumranet"); MODULE_LICENSE("GPL"); @@ -587,10 +589,10 @@ static inline void ept_sync_individual_addr(u64 eptp, gpa_t gpa) static unsigned long vmcs_readl(unsigned long field) { - unsigned long value = 0; + unsigned long value; - asm volatile (__ex(ASM_VMX_VMREAD_RDX_RAX) - : "+a"(value) : "d"(field) : "cc"); + asm volatile (__ex_clear(ASM_VMX_VMREAD_RDX_RAX, "%0") + : "=a"(value) : "d"(field) : "cc"); return value; } -- cgit v1.2.2