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Commit ca373932 authored by Anthony Liguori's avatar Anthony Liguori Committed by Avi Kivity
Browse files

x86: KVM guest: Add memory clobber to hypercalls 



Hypercalls can modify arbitrary regions of memory.  Make sure to indicate this
in the clobber list.  This fixes a hang when using KVM_GUEST kernel built with
GCC 4.3.0.

This was originally spotted and analyzed by Marcelo.

Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent b7279469

include/asm-x86/kvm_para.h

+10 −5
Original line number Diff line number Diff line
@@ -71,7 +71,8 @@ static inline long kvm_hypercall0(unsigned int nr) 
	long ret;

	asm volatile(KVM_HYPERCALL

		     : "=a"(ret)

		     : "a"(nr));

		     : "a"(nr)

		     : "memory");

	return ret;

}
@@ -80,7 +81,8 @@ static inline long kvm_hypercall1(unsigned int nr, unsigned long p1) 
	long ret;

	asm volatile(KVM_HYPERCALL

		     : "=a"(ret)

		     : "a"(nr), "b"(p1));

		     : "a"(nr), "b"(p1)

		     : "memory");

	return ret;

}
@@ -90,7 +92,8 @@ static inline long kvm_hypercall2(unsigned int nr, unsigned long p1, 
	long ret;

	asm volatile(KVM_HYPERCALL

		     : "=a"(ret)

		     : "a"(nr), "b"(p1), "c"(p2));

		     : "a"(nr), "b"(p1), "c"(p2)

		     : "memory");

	return ret;

}
@@ -100,7 +103,8 @@ static inline long kvm_hypercall3(unsigned int nr, unsigned long p1, 
	long ret;

	asm volatile(KVM_HYPERCALL

		     : "=a"(ret)

		     : "a"(nr), "b"(p1), "c"(p2), "d"(p3));

		     : "a"(nr), "b"(p1), "c"(p2), "d"(p3)

		     : "memory");

	return ret;

}
@@ -111,7 +115,8 @@ static inline long kvm_hypercall4(unsigned int nr, unsigned long p1, 
	long ret;

	asm volatile(KVM_HYPERCALL

		     : "=a"(ret)

		     : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4));

		     : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4)

		     : "memory");

	return ret;

}