On 2016-03-11 5:16 PM, Borislav Petkov wrote:
On Fri, Mar 11, 2016 at 08:18:23PM +0100, Paolo Bonzini wrote:Somebody got it wrong 10-ish years ago, and nobody has ever checked since. But, don't use qemu32 or qemu64. Use kvm32 and kvm64, or better something like the host you run on ("-cpu Nehalem", "-cpu SandyBridge", "-cpu Haswell-noTSX" etc.).Paul, Richard, how about it?
I'm not Paul/Richard, but I can answer :) We want a more generic cpu for these qemu references. Something that doesn't vary, since it runs on any number of hosts. There are some horrible issues we've had to solve with -cpu host in the past. Switching to the kvm cpu type should work, plus we can add cpu extensions on the fly as necessary. That's definitely a valid outcome from this discussion .. a cpu type that doesn't shoot through the middle of the expected capabilities .. and a bonus if the kernel or qemu can be tweaked to survive a similar mix up in the flags in the future. Cheers, Bruce
I really, really should fix those defaults...Here's a start, while I have everything fresh in my head. --- From: Borislav Petkov <bp@xxxxxxx> Date: Fri, 11 Mar 2016 23:11:05 +0100 Subject: [PATCH] target-i386/cpu: Correct MTRR and PAT feature bits Pentium Pro had MTRRs but not PAT, PAT support appeared in Pentium III. Fix all defines. Signed-off-by: Borislav Petkov <bp@xxxxxxx> --- target-i386/cpu.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/target-i386/cpu.c b/target-i386/cpu.c index 0f38d1eae317..fa7ea4a8c229 100644 --- a/target-i386/cpu.c +++ b/target-i386/cpu.c @@ -308,12 +308,12 @@ static const char *cpuid_6_feature_name[] = { #define PENTIUM_FEATURES (I486_FEATURES | CPUID_DE | CPUID_TSC | \ CPUID_MSR | CPUID_MCE | CPUID_CX8 | CPUID_MMX | CPUID_APIC) #define PENTIUM2_FEATURES (PENTIUM_FEATURES | CPUID_PAE | CPUID_SEP | \ - CPUID_MTRR | CPUID_PGE | CPUID_MCA | CPUID_CMOV | CPUID_PAT | \ + CPUID_MTRR | CPUID_PGE | CPUID_MCA | CPUID_CMOV | \ CPUID_PSE36 | CPUID_FXSR) -#define PENTIUM3_FEATURES (PENTIUM2_FEATURES | CPUID_SSE) +#define PENTIUM3_FEATURES (PENTIUM2_FEATURES | CPUID_SSE | CPUID_PAT) #define PPRO_FEATURES (CPUID_FP87 | CPUID_DE | CPUID_PSE | CPUID_TSC | \ CPUID_MSR | CPUID_MCE | CPUID_CX8 | CPUID_PGE | CPUID_CMOV | \ - CPUID_PAT | CPUID_FXSR | CPUID_MMX | CPUID_SSE | CPUID_SSE2 | \ + CPUID_MTRR | CPUID_FXSR | CPUID_MMX | CPUID_SSE | CPUID_SSE2 | \ CPUID_PAE | CPUID_SEP | CPUID_APIC) #define TCG_FEATURES (CPUID_FP87 | CPUID_PSE | CPUID_TSC | CPUID_MSR | \
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