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[Qemu-devel] [PATCH 5/6] remove CPUID host hacks
From: |
Andre Przywara |
Subject: |
[Qemu-devel] [PATCH 5/6] remove CPUID host hacks |
Date: |
Thu, 25 Jun 2009 00:08:03 +0200 |
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 <address@hidden>
---
target-i386/helper.c | 27 +++++----------------------
1 files changed, 5 insertions(+), 22 deletions(-)
diff --git a/target-i386/helper.c b/target-i386/helper.c
index 2e77570..bcaaab7 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -1643,28 +1643,11 @@ 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 */
- *ecx &= ~4UL;
- /* 3dnow */
- *edx &= ~0xc0000000;
+ /* Nested SVM not yet supported in KVM */
+ *ecx &= ~CPUID_EXT3_SVM;
+ } else {
+ /* AMD 3DNow! is not supported in QEMU */
+ *edx &= ~(CPUID_EXT2_3DNOW | CPUID_EXT2_3DNOWEXT);
}
break;
case 0x80000002:
--
1.6.1.3
- [Qemu-devel] [PATCH 0/6] Add -cpu host CPU type, Andre Przywara, 2009/06/24
- [Qemu-devel] [PATCH 1/6] allow hypervisor CPUID bit to be overriden, Andre Przywara, 2009/06/24
- [Qemu-devel] [PATCH 5/6] remove CPUID host hacks,
Andre Przywara <=
- [Qemu-devel] [PATCH 4/6] fix KVMs GET_SUPPORTED_CPUID feature usage, Andre Przywara, 2009/06/24
- [Qemu-devel] [PATCH 3/6] CPUID Fn8000_0001.EAX is family/model/stepping, not features, Andre Przywara, 2009/06/24
- [Qemu-devel] [PATCH 6/6] preserve the hypervisor bit while KVM trims the CPUID bits, Andre Przywara, 2009/06/24
- [Qemu-devel] [PATCH 2/6] introduce -cpu host target, Andre Przywara, 2009/06/24