On 01.07.2009, at 09:22, Andre Przywara wrote:
KVM provides an in-kernel feature to disable CPUID bits that are not
present in the current host. So there is no need here to duplicate
this
work. Additionally allows 3DNow! on capable processors, since the
restriction seems to apply to QEMU/TCG only.
Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
target-i386/helper.c | 22 +---------------------
1 files changed, 1 insertions(+), 21 deletions(-)
This is a rebased version of the qemu.git patch, which caused merge
conflicts.
Please apply!
Regards,
Andre.
diff --git a/target-i386/helper.c b/target-i386/helper.c
index d76c224..30e1d77 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -1645,29 +1645,9 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t
index, uint32_t count,
*edx = env->cpuid_ext2_features;
if (kvm_enabled()) {
- uint32_t h_eax, h_edx;
-
- host_cpuid(index, 0, &h_eax, NULL, NULL, &h_edx);
-
- /* disable CPU features that the host does not support */
-
- /* long mode */
- if ((h_edx & 0x20000000) == 0 /* || !lm_capable_kernel
*/)
- *edx &= ~0x20000000;
- /* syscall */
- if ((h_edx & 0x00000800) == 0)
- *edx &= ~0x00000800;
- /* nx */
- if ((h_edx & 0x00100000) == 0)
- *edx &= ~0x00100000;
-
- /* disable CPU features that KVM cannot support */
-
- /* svm */
+ /* disable nested svm if not explicitly requested */
if (!kvm_nested)
*ecx &= ~CPUID_EXT3_SVM;
- /* 3dnow */
- *edx &= ~0xc0000000;
I don't know why this is in, but it's definitely in a kvm_enabled() if
statement, so it's not because of TCG :-).
Also kvm_nested should control the svm bit in the qemu description
already. Preferably before the +/-feature bits are interpreted.
... this would lead to total removal of that hack function :-).
Alex
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