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 <[email protected]> --- arch/x86/include/asm/kvm_host.h | 6 +++++- arch/x86/kvm/vmx.c | 8 +++++--- 2 files changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index d2ac8e2..db4b654 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -830,11 +830,12 @@ enum { asmlinkage void kvm_spurious_fault(void); extern bool kvm_rebooting; -#define __kvm_handle_fault_on_reboot(insn) \ +#define ____kvm_handle_fault_on_reboot(insn, cleanup_insn) \ "666: " insn "\n\t" \ "668: \n\t" \ ".pushsection .fixup, \"ax\" \n" \ "667: \n\t" \ + cleanup_insn "\n\t" \ "cmpb $0, kvm_rebooting \n\t" \ "jne 668b \n\t" \ __ASM_SIZE(push) " $666b \n\t" \ @@ -844,6 +845,9 @@ extern bool kvm_rebooting; _ASM_PTR " 666b, 667b \n\t" \ ".popsection" +#define __kvm_handle_fault_on_reboot(insn) \ + ____kvm_handle_fault_on_reboot(insn, "") + #define KVM_ARCH_WANT_MMU_NOTIFIER int kvm_unmap_hva(struct kvm *kvm, unsigned long hva); int kvm_age_hva(struct kvm *kvm, unsigned long hva); diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 4c3fa0f..3df6b2c 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; } -- 1.7.4.3 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
