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KVM/x86: Use 32bit xor to clear register 

x86_64 zero-extends 32bit xor to a full 64bit register. Use %k asm
operand modifier to force 32bit register and save 268 bytes in kvm.o

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Uros Bizjak 2018-10-11 19:40:45 +02:00 committed by Paolo Bonzini
parent 4b1e54786e
commit 44c2d667ce
1 changed files with 2 additions and 2 deletions
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4
arch/x86/kvm/vmx.c
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@ -61,7 +61,7 @@
#define __ex(x) __kvm_handle_fault_on_reboot(x)
#define __ex_clear(x, reg) \
____kvm_handle_fault_on_reboot(x, "xor " reg " , " reg)
____kvm_handle_fault_on_reboot(x, "xorl " reg " , " reg)
MODULE_AUTHOR("Qumranet");
MODULE_LICENSE("GPL");
@ -2312,7 +2312,7 @@ static __always_inline unsigned long __vmcs_readl(unsigned long field)
{
unsigned long value;
asm volatile (__ex_clear("vmread %1, %0", "%0")
asm volatile (__ex_clear("vmread %1, %0", "%k0")
: "=r"(value) : "r"(field));
return value;
}