* [Qemu-devel] [PATCH] forward cpuid leaves when using -cpu host @ 2013-08-27 20:38 Benoît Canet 2013-08-27 20:38 ` [Qemu-devel] [PATCH] i386: forward CPUID cache leaves when -cpu host is used Benoît Canet 2013-09-02 12:45 ` [Qemu-devel] [PATCH] forward cpuid leaves when using -cpu host Benoît Canet 0 siblings, 2 replies; 6+ messages in thread From: Benoît Canet @ 2013-08-27 20:38 UTC (permalink / raw) To: qemu-devel; +Cc: imammedo, Benoît Canet, ehabkost, afaerber This patch uses directly cpuid_host to forward the informations instead of storing a variable number of leaves in the cpu states. Benoît Canet (1): i386: forward CPUID cache leaves when -cpu host is used target-i386/cpu.c | 19 +++++++++++++++++++ target-i386/cpu.h | 1 + 2 files changed, 20 insertions(+) -- 1.7.10.4 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Qemu-devel] [PATCH] i386: forward CPUID cache leaves when -cpu host is used 2013-08-27 20:38 [Qemu-devel] [PATCH] forward cpuid leaves when using -cpu host Benoît Canet @ 2013-08-27 20:38 ` Benoît Canet 2013-09-02 12:55 ` Andreas Färber 2013-09-02 12:45 ` [Qemu-devel] [PATCH] forward cpuid leaves when using -cpu host Benoît Canet 1 sibling, 1 reply; 6+ messages in thread From: Benoît Canet @ 2013-08-27 20:38 UTC (permalink / raw) To: qemu-devel; +Cc: imammedo, Benoît Canet, ehabkost, afaerber Some users running cpu intensive tasks checking the cache CPUID leaves at startup and making decisions based on the result reported that the guest was not reflecting the host CPUID leaves when -cpu host is used. This patch fix this. Signed-off-by: Benoit Canet <benoit@irqsave.net> --- target-i386/cpu.c | 19 +++++++++++++++++++ target-i386/cpu.h | 1 + 2 files changed, 20 insertions(+) diff --git a/target-i386/cpu.c b/target-i386/cpu.c index 42c5de0..2c8eaf7 100644 --- a/target-i386/cpu.c +++ b/target-i386/cpu.c @@ -374,6 +374,7 @@ typedef struct x86_def_t { int stepping; FeatureWordArray features; char model_id[48]; + bool fwd_cpuid_cache_leaves; } x86_def_t; #define I486_FEATURES (CPUID_FP87 | CPUID_VME | CPUID_PSE) @@ -1027,6 +1028,7 @@ static void kvm_cpu_fill_host(x86_def_t *x86_cpu_def) assert(kvm_enabled()); x86_cpu_def->name = "host"; + x86_cpu_def->fwd_cpuid_cache_leaves = true; host_cpuid(0x0, 0, &eax, &ebx, &ecx, &edx); x86_cpu_vendor_words2str(x86_cpu_def->vendor, ebx, edx, ecx); @@ -1776,6 +1778,7 @@ static void cpu_x86_register(X86CPU *cpu, const char *name, Error **errp) env->features[FEAT_C000_0001_EDX] = def->features[FEAT_C000_0001_EDX]; env->features[FEAT_7_0_EBX] = def->features[FEAT_7_0_EBX]; env->cpuid_xlevel2 = def->xlevel2; + env->fwd_cpuid_cache_leaves = def->fwd_cpuid_cache_leaves; object_property_set_str(OBJECT(cpu), def->model_id, "model-id", errp); } @@ -1949,6 +1952,10 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, } break; case 2: + if (env->fwd_cpuid_cache_leaves) { + host_cpuid(0x2, 0, eax, ebx, ecx, edx); + break; + } /* cache info: needed for Pentium Pro compatibility */ *eax = 1; *ebx = 0; @@ -1956,6 +1963,10 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, *edx = 0x2c307d; break; case 4: + if (env->fwd_cpuid_cache_leaves) { + host_cpuid(0x4, count, eax, ebx, ecx, edx); + break; + } /* cache info: needed for Core compatibility */ if (cs->nr_cores > 1) { *eax = (cs->nr_cores - 1) << 26; @@ -2102,6 +2113,10 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, break; case 0x80000005: /* cache info (L1 cache) */ + if (env->fwd_cpuid_cache_leaves) { + host_cpuid(0x80000005, 0, eax, ebx, ecx, edx); + break; + } *eax = 0x01ff01ff; *ebx = 0x01ff01ff; *ecx = 0x40020140; @@ -2109,6 +2124,10 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, break; case 0x80000006: /* cache info (L2 cache) */ + if (env->fwd_cpuid_cache_leaves) { + host_cpuid(0x80000006, 0, eax, ebx, ecx, edx); + break; + } *eax = 0; *ebx = 0x42004200; *ecx = 0x02008140; diff --git a/target-i386/cpu.h b/target-i386/cpu.h index 8a3d0fd..1ec32fa 100644 --- a/target-i386/cpu.h +++ b/target-i386/cpu.h @@ -865,6 +865,7 @@ typedef struct CPUX86State { bool tsc_valid; int tsc_khz; void *kvm_xsave_buf; + bool fwd_cpuid_cache_leaves; /* in order to simplify APIC support, we leave this pointer to the user */ -- 1.7.10.4 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] i386: forward CPUID cache leaves when -cpu host is used 2013-08-27 20:38 ` [Qemu-devel] [PATCH] i386: forward CPUID cache leaves when -cpu host is used Benoît Canet @ 2013-09-02 12:55 ` Andreas Färber 2013-09-02 13:09 ` Eduardo Habkost 0 siblings, 1 reply; 6+ messages in thread From: Andreas Färber @ 2013-09-02 12:55 UTC (permalink / raw) To: Benoît Canet Cc: imammedo, qemu-devel, kvm@vger.kernel.org list, ehabkost Hi, "target-i386:" please. Am 27.08.2013 22:38, schrieb Benoît Canet: > Some users running cpu intensive tasks checking the cache CPUID leaves at > startup and making decisions based on the result reported that the guest was > not reflecting the host CPUID leaves when -cpu host is used. > > This patch fix this. > > Signed-off-by: Benoit Canet <benoit@irqsave.net> > --- > target-i386/cpu.c | 19 +++++++++++++++++++ > target-i386/cpu.h | 1 + > 2 files changed, 20 insertions(+) > > diff --git a/target-i386/cpu.c b/target-i386/cpu.c > index 42c5de0..2c8eaf7 100644 > --- a/target-i386/cpu.c > +++ b/target-i386/cpu.c > @@ -374,6 +374,7 @@ typedef struct x86_def_t { > int stepping; > FeatureWordArray features; > char model_id[48]; > + bool fwd_cpuid_cache_leaves; > } x86_def_t; > > #define I486_FEATURES (CPUID_FP87 | CPUID_VME | CPUID_PSE) > @@ -1027,6 +1028,7 @@ static void kvm_cpu_fill_host(x86_def_t *x86_cpu_def) > assert(kvm_enabled()); > > x86_cpu_def->name = "host"; > + x86_cpu_def->fwd_cpuid_cache_leaves = true; > host_cpuid(0x0, 0, &eax, &ebx, &ecx, &edx); > x86_cpu_vendor_words2str(x86_cpu_def->vendor, ebx, edx, ecx); > > @@ -1776,6 +1778,7 @@ static void cpu_x86_register(X86CPU *cpu, const char *name, Error **errp) > env->features[FEAT_C000_0001_EDX] = def->features[FEAT_C000_0001_EDX]; > env->features[FEAT_7_0_EBX] = def->features[FEAT_7_0_EBX]; > env->cpuid_xlevel2 = def->xlevel2; > + env->fwd_cpuid_cache_leaves = def->fwd_cpuid_cache_leaves; > > object_property_set_str(OBJECT(cpu), def->model_id, "model-id", errp); > } > @@ -1949,6 +1952,10 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, > } > break; > case 2: > + if (env->fwd_cpuid_cache_leaves) { > + host_cpuid(0x2, 0, eax, ebx, ecx, edx); > + break; > + } > /* cache info: needed for Pentium Pro compatibility */ > *eax = 1; > *ebx = 0; > @@ -1956,6 +1963,10 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, > *edx = 0x2c307d; > break; > case 4: > + if (env->fwd_cpuid_cache_leaves) { > + host_cpuid(0x4, count, eax, ebx, ecx, edx); > + break; > + } > /* cache info: needed for Core compatibility */ > if (cs->nr_cores > 1) { > *eax = (cs->nr_cores - 1) << 26; > @@ -2102,6 +2113,10 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, > break; > case 0x80000005: > /* cache info (L1 cache) */ > + if (env->fwd_cpuid_cache_leaves) { > + host_cpuid(0x80000005, 0, eax, ebx, ecx, edx); > + break; > + } > *eax = 0x01ff01ff; > *ebx = 0x01ff01ff; > *ecx = 0x40020140; > @@ -2109,6 +2124,10 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, > break; > case 0x80000006: > /* cache info (L2 cache) */ > + if (env->fwd_cpuid_cache_leaves) { > + host_cpuid(0x80000006, 0, eax, ebx, ecx, edx); > + break; > + } > *eax = 0; > *ebx = 0x42004200; > *ecx = 0x02008140; This hunk may trivially conflict with Eduardo's cache flags cleanup. > diff --git a/target-i386/cpu.h b/target-i386/cpu.h > index 8a3d0fd..1ec32fa 100644 > --- a/target-i386/cpu.h > +++ b/target-i386/cpu.h > @@ -865,6 +865,7 @@ typedef struct CPUX86State { > bool tsc_valid; > int tsc_khz; > void *kvm_xsave_buf; > + bool fwd_cpuid_cache_leaves; > > /* in order to simplify APIC support, we leave this pointer to the > user */ Please place the field in X86CPU instead and document it. Otherwise patch looks okay to me on a brief sight; but since this is about -cpu host I would prefer this to go through uq/master once fixed or at least to get some acks. Regards, Andreas -- SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] i386: forward CPUID cache leaves when -cpu host is used 2013-09-02 12:55 ` Andreas Färber @ 2013-09-02 13:09 ` Eduardo Habkost 0 siblings, 0 replies; 6+ messages in thread From: Eduardo Habkost @ 2013-09-02 13:09 UTC (permalink / raw) To: Andreas Färber Cc: imammedo, Benoît Canet, kvm@vger.kernel.org list, qemu-devel On Mon, Sep 02, 2013 at 02:55:36PM +0200, Andreas Färber wrote: [...] > > diff --git a/target-i386/cpu.h b/target-i386/cpu.h > > index 8a3d0fd..1ec32fa 100644 > > --- a/target-i386/cpu.h > > +++ b/target-i386/cpu.h > > @@ -865,6 +865,7 @@ typedef struct CPUX86State { > > bool tsc_valid; > > int tsc_khz; > > void *kvm_xsave_buf; > > + bool fwd_cpuid_cache_leaves; > > > > /* in order to simplify APIC support, we leave this pointer to the > > user */ > > Please place the field in X86CPU instead and document it. While moving it, I believe the name can be made clearer. I would name it "fwd_host_cache_info" or something like that, to make it clear that it will expose the _host CPU_ cache information to the guest. -- Eduardo ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] forward cpuid leaves when using -cpu host 2013-08-27 20:38 [Qemu-devel] [PATCH] forward cpuid leaves when using -cpu host Benoît Canet 2013-08-27 20:38 ` [Qemu-devel] [PATCH] i386: forward CPUID cache leaves when -cpu host is used Benoît Canet @ 2013-09-02 12:45 ` Benoît Canet 2013-09-02 12:58 ` Eduardo Habkost 1 sibling, 1 reply; 6+ messages in thread From: Benoît Canet @ 2013-09-02 12:45 UTC (permalink / raw) To: qemu-devel; +Cc: imammedo, ehabkost, afaerber Ping, I am aware that this patch must be a QObject/CPUState monstruosity but I don't see how I could store the fact that the cpu derive from a "host" type cpu. The alternative would be to remember a variable number of leaves and serving them to the guest as needed but I don't find that much cleaner. Best regards Benoît > Le Tuesday 27 Aug 2013 à 22:38:25 (+0200), Benoît Canet a écrit : > This patch uses directly cpuid_host to forward the informations instead of > storing a variable number of leaves in the cpu states. > > Benoît Canet (1): > i386: forward CPUID cache leaves when -cpu host is used > > target-i386/cpu.c | 19 +++++++++++++++++++ > target-i386/cpu.h | 1 + > 2 files changed, 20 insertions(+) > > -- > 1.7.10.4 > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] [PATCH] forward cpuid leaves when using -cpu host 2013-09-02 12:45 ` [Qemu-devel] [PATCH] forward cpuid leaves when using -cpu host Benoît Canet @ 2013-09-02 12:58 ` Eduardo Habkost 0 siblings, 0 replies; 6+ messages in thread From: Eduardo Habkost @ 2013-09-02 12:58 UTC (permalink / raw) To: Benoît Canet; +Cc: imammedo, qemu-devel, afaerber On Mon, Sep 02, 2013 at 02:45:48PM +0200, Benoît Canet wrote: > > Ping, > > I am aware that this patch must be a QObject/CPUState monstruosity but I don't > see how I could store the fact that the cpu derive from a "host" type cpu. > The alternative would be to remember a variable number of leaves and serving > them to the guest as needed but I don't find that much cleaner. The idea makes sense for -cpu host, and it is not intrusive for all other CPU models. I just didn't take the time to look at the code to send my "reviewed-by:" line yet. I plan to take a look today or tomorrow. > > Best regards > > Benoît > > > Le Tuesday 27 Aug 2013 à 22:38:25 (+0200), Benoît Canet a écrit : > > This patch uses directly cpuid_host to forward the informations instead of > > storing a variable number of leaves in the cpu states. > > > > Benoît Canet (1): > > i386: forward CPUID cache leaves when -cpu host is used > > > > target-i386/cpu.c | 19 +++++++++++++++++++ > > target-i386/cpu.h | 1 + > > 2 files changed, 20 insertions(+) > > > > -- > > 1.7.10.4 > > -- Eduardo ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2013-09-02 13:10 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2013-08-27 20:38 [Qemu-devel] [PATCH] forward cpuid leaves when using -cpu host Benoît Canet 2013-08-27 20:38 ` [Qemu-devel] [PATCH] i386: forward CPUID cache leaves when -cpu host is used Benoît Canet 2013-09-02 12:55 ` Andreas Färber 2013-09-02 13:09 ` Eduardo Habkost 2013-09-02 12:45 ` [Qemu-devel] [PATCH] forward cpuid leaves when using -cpu host Benoît Canet 2013-09-02 12:58 ` Eduardo Habkost
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