On Mon, Dec 10, 2018 at 05:47:25PM -0200, Eduardo Habkost wrote: > On Mon, Dec 10, 2018 at 07:41:53PM +0100, Borislav Petkov wrote: > > On Mon, Dec 10, 2018 at 04:37:30PM -0200, Eduardo Habkost wrote: > > > It isn't as simply as reverting commit 33b5e8c03ae7, but we can > > > surely re-add RDTSCP on pc-*-4.0 and newer. > > > > Sure. If you could only point me to an example how to add that to > > pc-*-4.0 and newer, I'll gladly cook up a patch and test it. > > Sorry, I forgot to reply to this part. > > See commit 33b5e8c03ae7 for reference. The differences will be: > * Instead of removing RDTSCP from builtin_x86_defs, you'll be adding it. > * Instead of adding rdtscp=on entries to PC_COMPAT_2_4, you'll > be adding rdtscp=off entries to PC_COMPAT_3_1. > > PC_COMPAT_3_1 is added by the patch that creates the 4.0 > machine-types. You can find it on my machine-next branch at: > > http://github.com/ehabkost/qemu Thanks for the patient explanation, diff below ontop of your branch. It is notable to point out that Opteron_G2 - it being family 0xf, model 6 - should not deal with RDTSCP as it doesn't have it. Although looking at the docs, they say it does but I *have* a K8 laptop which I just checked and it *doesn't* have RDTSCP in CPUID. So lemme clarify that aspect first with folks. :) --- diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h index 9d29c4b1df2a..ebc28e816b04 100644 --- a/include/hw/i386/pc.h +++ b/include/hw/i386/pc.h @@ -296,6 +296,19 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *); #define PC_COMPAT_3_1 \ HW_COMPAT_3_1 \ + {\ + .driver = "Opteron_G3" "-" TYPE_X86_CPU,\ + .property = "rdtscp",\ + .value = "off",\ + },{\ + .driver = "Opteron_G4" "-" TYPE_X86_CPU,\ + .property = "rdtscp",\ + .value = "off",\ + },{\ + .driver = "Opteron_G5" "-" TYPE_X86_CPU,\ + .property = "rdtscp",\ + .value = "off",\ + }, #define PC_COMPAT_3_0 \ HW_COMPAT_3_0 \ @@ -527,10 +540,6 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *); .driver = "qemu32" "-" TYPE_X86_CPU,\ .property = "popcnt",\ .value = "on",\ - },{\ - .driver = "Opteron_G2" "-" TYPE_X86_CPU,\ - .property = "rdtscp",\ - .value = "on",\ },{\ .driver = "Opteron_G3" "-" TYPE_X86_CPU,\ .property = "rdtscp",\ diff --git a/qemu-doc.texi b/qemu-doc.texi index f7ad1dfe4b69..913b2ef68d54 100644 --- a/qemu-doc.texi +++ b/qemu-doc.texi @@ -37,6 +37,7 @@ * QEMU System emulator for non PC targets:: * QEMU Guest Agent:: * QEMU User space emulator:: +* System requirements:: * Implementation notes:: * Deprecated features:: * Supported build platforms:: @@ -2813,6 +2814,13 @@ Act as if the host page size was 'pagesize' bytes Run the emulation in single step mode. @end table +@node System requirements +@chapter System requirements + +@section KVM kernel module + +On x86_64 hosts, the default set of CPU features enabled by the KVM accelerator +require the host to be running Linux v4.5 or newer. @include qemu-tech.texi diff --git a/target/i386/cpu.c b/target/i386/cpu.c index f81d35e1f914..a7def11b27cd 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -2706,7 +2706,6 @@ static X86CPUDefinition builtin_x86_defs[] = { CPUID_DE | CPUID_FP87, .features[FEAT_1_ECX] = CPUID_EXT_CX16 | CPUID_EXT_SSE3, - /* Missing: CPUID_EXT2_RDTSCP */ .features[FEAT_8000_0001_EDX] = CPUID_EXT2_LM | CPUID_EXT2_NX | CPUID_EXT2_SYSCALL, .features[FEAT_8000_0001_ECX] = @@ -2730,9 +2729,9 @@ static X86CPUDefinition builtin_x86_defs[] = { .features[FEAT_1_ECX] = CPUID_EXT_POPCNT | CPUID_EXT_CX16 | CPUID_EXT_MONITOR | CPUID_EXT_SSE3, - /* Missing: CPUID_EXT2_RDTSCP */ .features[FEAT_8000_0001_EDX] = - CPUID_EXT2_LM | CPUID_EXT2_NX | CPUID_EXT2_SYSCALL, + CPUID_EXT2_LM | CPUID_EXT2_NX | CPUID_EXT2_SYSCALL | + CPUID_EXT2_RDTSCP, .features[FEAT_8000_0001_ECX] = CPUID_EXT3_MISALIGNSSE | CPUID_EXT3_SSE4A | CPUID_EXT3_ABM | CPUID_EXT3_SVM | CPUID_EXT3_LAHF_LM, @@ -2757,10 +2756,9 @@ static X86CPUDefinition builtin_x86_defs[] = { CPUID_EXT_POPCNT | CPUID_EXT_SSE42 | CPUID_EXT_SSE41 | CPUID_EXT_CX16 | CPUID_EXT_SSSE3 | CPUID_EXT_PCLMULQDQ | CPUID_EXT_SSE3, - /* Missing: CPUID_EXT2_RDTSCP */ .features[FEAT_8000_0001_EDX] = CPUID_EXT2_LM | CPUID_EXT2_PDPE1GB | CPUID_EXT2_NX | - CPUID_EXT2_SYSCALL, + CPUID_EXT2_SYSCALL | CPUID_EXT2_RDTSCP, .features[FEAT_8000_0001_ECX] = CPUID_EXT3_FMA4 | CPUID_EXT3_XOP | CPUID_EXT3_3DNOWPREFETCH | CPUID_EXT3_MISALIGNSSE | @@ -2788,10 +2786,9 @@ static X86CPUDefinition builtin_x86_defs[] = { CPUID_EXT_AES | CPUID_EXT_POPCNT | CPUID_EXT_SSE42 | CPUID_EXT_SSE41 | CPUID_EXT_CX16 | CPUID_EXT_FMA | CPUID_EXT_SSSE3 | CPUID_EXT_PCLMULQDQ | CPUID_EXT_SSE3, - /* Missing: CPUID_EXT2_RDTSCP */ .features[FEAT_8000_0001_EDX] = CPUID_EXT2_LM | CPUID_EXT2_PDPE1GB | CPUID_EXT2_NX | - CPUID_EXT2_SYSCALL, + CPUID_EXT2_SYSCALL | CPUID_EXT2_RDTSCP, .features[FEAT_8000_0001_ECX] = CPUID_EXT3_TBM | CPUID_EXT3_FMA4 | CPUID_EXT3_XOP | CPUID_EXT3_3DNOWPREFETCH | CPUID_EXT3_MISALIGNSSE | -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.
