Commit 5e520e62 authored by Avi Kivity's avatar Avi Kivity
Browse files

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: default avatarAvi Kivity <avi@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 7b105ca2

arch/x86/include/asm/kvm_host.h

+5 −1
Original line number Diff line number Diff line
@@ -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);

arch/x86/kvm/vmx.c

+5 −3
Original line number Diff line number Diff line
@@ -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;

}