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authorAvi Kivity <avi@redhat.com>2009-05-11 14:21:10 +0300
committerGreg Kroah-Hartman <gregkh@suse.de>2009-05-18 16:35:18 -0700
commita6ddabcdf09bf394de04ca5c772129cb8fc6e179 (patch)
treef7cb1c9a7735749acd30e8393e87f2e70a1c3c2f /arch
parentefee69d7e0f1ddfec97549eee0a8b63750eb67f7 (diff)
KVM: SVM: Remove port 80 passthrough
commit 99f85a28a78e96d28907fe036e1671a218fee597 upstream. KVM optimizes guest port 80 accesses by passthing them through to the host. Some AMD machines die on port 80 writes, allowing the guest to hard-lock the host. Remove the port passthrough to avoid the problem. Reported-by: Piotr Jaroszyński <p.jaroszynski@gmail.com> Tested-by: Piotr Jaroszyński <p.jaroszynski@gmail.com> Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/svm.c1
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index da568212966a..dd8eeeae5979 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -411,7 +411,6 @@ static __init int svm_hardware_setup(void)
iopm_va = page_address(iopm_pages);
memset(iopm_va, 0xff, PAGE_SIZE * (1 << IOPM_ALLOC_ORDER));
- clear_bit(0x80, iopm_va); /* allow direct access to PC debug port */
iopm_base = page_to_pfn(iopm_pages) << PAGE_SHIFT;
if (boot_cpu_has(X86_FEATURE_NX))