Messages in this thread Patch in this message | | | Subject | [PATCH] KVM: Fix asm constraints | From | Avi Kivity <> | Date | Sun, 12 Nov 2006 13:52:27 -0000 |
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The change to directly encoded vmx opcodes (rather than asm instructions) forced us to pass the address of phys_addr as an operand, rather than its contents. However, nothing forces gcc to commit the contents of the variable to memory, so add an explicit "m" constraint.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Index: linux-2.6/drivers/kvm/kvm_main.c =================================================================== --- linux-2.6.orig/drivers/kvm/kvm_main.c +++ linux-2.6/drivers/kvm/kvm_main.c @@ -371,7 +371,8 @@ static void vmcs_clear(struct vmcs *vmcs u8 error; asm volatile (ASM_VMX_VMCLEAR_RAX "; setna %0" - : "=g"(error) : "a"(&phys_addr) : "cc", "memory" ); + : "=g"(error) : "a"(&phys_addr), "m"(phys_addr) + : "cc", "memory"); if (error) printk(KERN_ERR "kvm: vmclear fail: %p/%llx\n", vmcs, phys_addr); @@ -414,7 +415,8 @@ static struct kvm_vcpu *__vcpu_load(stru per_cpu(current_vmcs, cpu) = vcpu->vmcs; asm volatile (ASM_VMX_VMPTRLD_RAX "; setna %0" - : "=g"(error) : "a"(&phys_addr) : "cc" ); + : "=g"(error) : "a"(&phys_addr), "m"(phys_addr) + : "cc"); if (error) printk(KERN_ERR "kvm: vmptrld %p/%llx fail\n", vcpu->vmcs, phys_addr); @@ -537,7 +539,8 @@ static __init void kvm_enable(void *garb /* enable and lock */ wrmsrl(MSR_IA32_FEATURE_CONTROL, old | 5); write_cr4(read_cr4() | CR4_VMXE); /* FIXME: not cpu hotplug safe */ - asm volatile (ASM_VMX_VMXON_RAX : : "a"(&phys_addr) : "memory", "cc"); + asm volatile (ASM_VMX_VMXON_RAX : : "a"(&phys_addr), "m"(phys_addr) + : "memory", "cc"); } static void kvm_disable(void *garbage) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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