* [Qemu-devel] [PATCH] target-i386: Reenable RDTSCP support on Opteron_G[345] CPU models [not found] ` <20181211153017.GN921@redhat.com> @ 2018-12-11 16:14 ` Borislav Petkov 2018-12-12 19:52 ` Eduardo Habkost 0 siblings, 1 reply; 4+ messages in thread From: Borislav Petkov @ 2018-12-11 16:14 UTC (permalink / raw) To: Daniel P. Berrangé, Eduardo Habkost Cc: Paolo Bonzini, Jörg Rödel, Andre Przywara, kvm ML, lkml, Tom Lendacky, Eric Blake, qemu-devel + qemu-devel. On Tue, Dec 11, 2018 at 03:30:17PM +0000, Daniel P. Berrangé wrote: > Great, then, this is a non-issue - we just need to mention that fact > in the commit that sets the min version for the kernel Ok, here's a first draft ontop of Eduardo's machine-next branch from http://github.com/ehabkost/qemu Also, thanks for the help Eduardo! :-) --- From: Borislav Petkov <bp@suse.de> Date: Tue, 11 Dec 2018 17:01:00 +0100 The missing functionality was added ~3 years ago with the Linux commit 46896c73c1a4 ("KVM: svm: add support for RDTSCP") so reenable RDTSCP support on those CPU models. Opteron_G2 - being family 15, model 6, doesn't have RDTSCP support (the real hardware doesn't have it. K8 got RDTSCP support with the NPT models, i.e., models >= 0x40). Document the host's minimum required kernel version, while at it. Signed-off-by: Borislav Petkov <bp@suse.de> --- include/hw/i386/pc.h | 17 +++++++++++++---- qemu-doc.texi | 13 +++++++++++++ target/i386/cpu.c | 11 ++++------- 3 files changed, 30 insertions(+), 11 deletions(-) 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..16b955cbf985 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 +2814,18 @@ 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. + +The OpteronG[345] CPU models require KVM support for RDTSCP, which was +added with Linux 4.5 which is supported by the major distros. And even +if RHEL7 has kernel 3.10, KVM there has the required functionality there +to make it close to a 4.5 or newer kernel. @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 | -- 2.19.1 -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply. ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH] target-i386: Reenable RDTSCP support on Opteron_G[345] CPU models 2018-12-11 16:14 ` [Qemu-devel] [PATCH] target-i386: Reenable RDTSCP support on Opteron_G[345] CPU models Borislav Petkov @ 2018-12-12 19:52 ` Eduardo Habkost 2018-12-12 20:08 ` [Qemu-devel] [PATCH -v2] target-i386: Reenable RDTSCP support on Opteron_G[345] CPU models " Borislav Petkov 0 siblings, 1 reply; 4+ messages in thread From: Eduardo Habkost @ 2018-12-12 19:52 UTC (permalink / raw) To: Borislav Petkov Cc: Daniel P. Berrangé, Paolo Bonzini, Jörg Rödel, Andre Przywara, kvm ML, lkml, Tom Lendacky, Eric Blake, qemu-devel On Tue, Dec 11, 2018 at 05:14:40PM +0100, Borislav Petkov wrote: > + qemu-devel. > > On Tue, Dec 11, 2018 at 03:30:17PM +0000, Daniel P. Berrangé wrote: > > Great, then, this is a non-issue - we just need to mention that fact > > in the commit that sets the min version for the kernel > > Ok, here's a first draft ontop of Eduardo's machine-next branch from > http://github.com/ehabkost/qemu > > Also, thanks for the help Eduardo! :-) > > --- > From: Borislav Petkov <bp@suse.de> > Date: Tue, 11 Dec 2018 17:01:00 +0100 > > The missing functionality was added ~3 years ago with the Linux commit > > 46896c73c1a4 ("KVM: svm: add support for RDTSCP") > > so reenable RDTSCP support on those CPU models. > > Opteron_G2 - being family 15, model 6, doesn't have RDTSCP support > (the real hardware doesn't have it. K8 got RDTSCP support with the NPT > models, i.e., models >= 0x40). > > Document the host's minimum required kernel version, while at it. > > Signed-off-by: Borislav Petkov <bp@suse.de> > --- > include/hw/i386/pc.h | 17 +++++++++++++---- > qemu-doc.texi | 13 +++++++++++++ > target/i386/cpu.c | 11 ++++------- > 3 files changed, 30 insertions(+), 11 deletions(-) > > 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",\ > + }, This looks correct. > > #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",\ Why did you remove this entry from PC_COMPAT_2_4? We must keep compatibility with old behavior of Opteron_G2 on pc-2.4, even if the old behavior was incorrect. > },{\ > .driver = "Opteron_G3" "-" TYPE_X86_CPU,\ > .property = "rdtscp",\ > diff --git a/qemu-doc.texi b/qemu-doc.texi > index f7ad1dfe4b69..16b955cbf985 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 +2814,18 @@ 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. > + > +The OpteronG[345] CPU models require KVM support for RDTSCP, which was > +added with Linux 4.5 which is supported by the major distros. And even > +if RHEL7 has kernel 3.10, KVM there has the required functionality there > +to make it close to a 4.5 or newer kernel. > > @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 */ This is Opteron_G2, and feature is not being added. Looks correct. > .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, This is Opteron_G3. Looks correct. > .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, This is Opteron_G4. Looks correct. > .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, This is Opteron_G5. Looks correct. > .features[FEAT_8000_0001_ECX] = > CPUID_EXT3_TBM | CPUID_EXT3_FMA4 | CPUID_EXT3_XOP | > CPUID_EXT3_3DNOWPREFETCH | CPUID_EXT3_MISALIGNSSE | > -- > 2.19.1 > > -- > Regards/Gruss, > Boris. > > Good mailing practices for 400: avoid top-posting and trim the reply. -- Eduardo ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Qemu-devel] [PATCH -v2] target-i386: Reenable RDTSCP support on Opteron_G[345] CPU models CPU models 2018-12-12 19:52 ` Eduardo Habkost @ 2018-12-12 20:08 ` Borislav Petkov 2018-12-20 12:10 ` Eduardo Habkost 0 siblings, 1 reply; 4+ messages in thread From: Borislav Petkov @ 2018-12-12 20:08 UTC (permalink / raw) To: Eduardo Habkost Cc: Daniel P. Berrangé, Paolo Bonzini, Jörg Rödel, Andre Przywara, kvm ML, lkml, Tom Lendacky, Eric Blake, qemu-devel On Wed, Dec 12, 2018 at 05:52:35PM -0200, Eduardo Habkost wrote: > Why did you remove this entry from PC_COMPAT_2_4? > > We must keep compatibility with old behavior of Opteron_G2 on > pc-2.4, even if the old behavior was incorrect. Ok, hunk reverted. v2 below. Thx. --- From: Borislav Petkov <bp@suse.de> The missing functionality was added ~3 years ago with the Linux commit 46896c73c1a4 ("KVM: svm: add support for RDTSCP") so reenable RDTSCP support on those CPU models. Opteron_G2 - being family 15, model 6, doesn't have RDTSCP support (the real hardware doesn't have it. K8 got RDTSCP support with the NPT models, i.e., models >= 0x40). Document the host's minimum required kernel version, while at it. Signed-off-by: Borislav Petkov <bp@suse.de> --- v2: Keep Opteron_G2 in PC_COMPAT_2_4 unchanged. include/hw/i386/pc.h | 13 +++++++++++++ qemu-doc.texi | 13 +++++++++++++ target/i386/cpu.c | 11 ++++------- 3 files changed, 30 insertions(+), 7 deletions(-) diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h index 9d29c4b1df2a..236d962d2547 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 \ diff --git a/qemu-doc.texi b/qemu-doc.texi index f7ad1dfe4b69..16b955cbf985 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 +2814,18 @@ 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. + +The OpteronG[345] CPU models require KVM support for RDTSCP, which was +added with Linux 4.5 which is supported by the major distros. And even +if RHEL7 has kernel 3.10, KVM there has the required functionality there +to make it close to a 4.5 or newer kernel. @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 | -- 2.19.1 -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply. ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [Qemu-devel] [PATCH -v2] target-i386: Reenable RDTSCP support on Opteron_G[345] CPU models CPU models 2018-12-12 20:08 ` [Qemu-devel] [PATCH -v2] target-i386: Reenable RDTSCP support on Opteron_G[345] CPU models " Borislav Petkov @ 2018-12-20 12:10 ` Eduardo Habkost 0 siblings, 0 replies; 4+ messages in thread From: Eduardo Habkost @ 2018-12-20 12:10 UTC (permalink / raw) To: Borislav Petkov Cc: Daniel P. Berrangé, Paolo Bonzini, Jörg Rödel, Andre Przywara, kvm ML, lkml, Tom Lendacky, Eric Blake, qemu-devel On Wed, Dec 12, 2018 at 09:08:03PM +0100, Borislav Petkov wrote: > On Wed, Dec 12, 2018 at 05:52:35PM -0200, Eduardo Habkost wrote: > > Why did you remove this entry from PC_COMPAT_2_4? > > > > We must keep compatibility with old behavior of Opteron_G2 on > > pc-2.4, even if the old behavior was incorrect. > > Ok, hunk reverted. v2 below. > > Thx. > > --- > From: Borislav Petkov <bp@suse.de> > > The missing functionality was added ~3 years ago with the Linux commit > > 46896c73c1a4 ("KVM: svm: add support for RDTSCP") > > so reenable RDTSCP support on those CPU models. > > Opteron_G2 - being family 15, model 6, doesn't have RDTSCP support > (the real hardware doesn't have it. K8 got RDTSCP support with the NPT > models, i.e., models >= 0x40). > > Document the host's minimum required kernel version, while at it. > > Signed-off-by: Borislav Petkov <bp@suse.de> Queued, thanks. -- Eduardo ^ permalink raw reply [flat|nested] 4+ messages in thread
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2018-12-11 16:14 ` [Qemu-devel] [PATCH] target-i386: Reenable RDTSCP support on Opteron_G[345] CPU models Borislav Petkov
2018-12-12 19:52 ` Eduardo Habkost
2018-12-12 20:08 ` [Qemu-devel] [PATCH -v2] target-i386: Reenable RDTSCP support on Opteron_G[345] CPU models " Borislav Petkov
2018-12-20 12:10 ` Eduardo Habkost
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