| Message ID | 1357757632-1950-3-git-send-email-ehabkost@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Wed, Jan 09, 2013 at 04:53:42PM -0200, Eduardo Habkost wrote: > This is a cleanup that tries to solve two small issues: > > - We don't need a separate kvm_pv_eoi_features variable just to keep a > constant calculated at compile-time, and this style would require > adding a separate variable (that's declared twice because of the > CONFIG_KVM ifdef) for each feature that's going to be enabled/disable > by machine-type compat code. > - The pc-1.3 code is setting the kvm_pv_eoi flag on cpuid_kvm_features > even when KVM is disabled at runtime. This small incosistency in > the cpuid_kvm_features field isn't a problem today because > cpuid_kvm_features is ignored by the TCG code, but it may cause > unexpected problems later when refactoring the CPUID handling code. > > This patch eliminates the kvm_pv_eoi_features variable and simply uses > kvm_enabled() inside the enable_kvm_pv_eoi() compat function, so it > enables kvm_pv_eoi only if KVM is enabled. I believe this makes the > behavior of enable_kvm_pv_eoi() clearer and easier to understand. > > Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> > --- > Cc: kvm@vger.kernel.org > Cc: Michael S. Tsirkin <mst@redhat.com> > Cc: Gleb Natapov <gleb@redhat.com> > Cc: Marcelo Tosatti <mtosatti@redhat.com> > > Changes v2: > - Coding style fix > > Changes v3: > - Eliminate #ifdef by using the fake KVM_FEATURE_PV_EOI #define > > Changes v4: > - Check kvm_enabled() when actually using kvm_default_features > - Eliminate Yet Another #ifdef by using the fake KVM_FEATURE_* > #defines on kvm_default_features initialization > --- > target-i386/cpu.c | 16 ++++++---------- > 1 file changed, 6 insertions(+), 10 deletions(-) > > diff --git a/target-i386/cpu.c b/target-i386/cpu.c > index e4dc370..57a22b7 100644 > --- a/target-i386/cpu.c > +++ b/target-i386/cpu.c > @@ -206,22 +206,16 @@ typedef struct model_features_t { > int check_cpuid = 0; > int enforce_cpuid = 0; > > -#if defined(CONFIG_KVM) > static uint32_t kvm_default_features = (1 << KVM_FEATURE_CLOCKSOURCE) | > (1 << KVM_FEATURE_NOP_IO_DELAY) | > (1 << KVM_FEATURE_CLOCKSOURCE2) | > (1 << KVM_FEATURE_ASYNC_PF) | > (1 << KVM_FEATURE_STEAL_TIME) | > (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT); > -static const uint32_t kvm_pv_eoi_features = (0x1 << KVM_FEATURE_PV_EOI); > -#else > -static uint32_t kvm_default_features = 0; > -static const uint32_t kvm_pv_eoi_features = 0; > -#endif > > void enable_kvm_pv_eoi(void) > { > - kvm_default_features |= kvm_pv_eoi_features; > + kvm_default_features |= (1UL << KVM_FEATURE_PV_EOI); > } > > void host_cpuid(uint32_t function, uint32_t count, > @@ -1343,13 +1337,15 @@ static int cpu_x86_parse_featurestr(x86_def_t *x86_cpu_def, char *features) > unsigned int i; > char *featurestr; /* Single 'key=value" string being parsed */ > /* Features to be added */ > - FeatureWordArray plus_features = { > - [FEAT_KVM] = kvm_default_features, > - }; > + FeatureWordArray plus_features = { 0 }; > /* Features to be removed */ > FeatureWordArray minus_features = { 0 }; > uint32_t numvalue; > > + if (kvm_enabled()) { > + plus_features[FEAT_KVM] = kvm_default_features; > + } > + > add_flagname_to_bitmaps("hypervisor", plus_features); > > featurestr = features ? strtok(features, ",") : NULL; > -- > 1.7.11.7
On Wed, 9 Jan 2013 16:53:42 -0200 Eduardo Habkost <ehabkost@redhat.com> wrote: > This is a cleanup that tries to solve two small issues: > > - We don't need a separate kvm_pv_eoi_features variable just to keep a > constant calculated at compile-time, and this style would require > adding a separate variable (that's declared twice because of the > CONFIG_KVM ifdef) for each feature that's going to be enabled/disable > by machine-type compat code. > - The pc-1.3 code is setting the kvm_pv_eoi flag on cpuid_kvm_features > even when KVM is disabled at runtime. This small incosistency in > the cpuid_kvm_features field isn't a problem today because > cpuid_kvm_features is ignored by the TCG code, but it may cause > unexpected problems later when refactoring the CPUID handling code. > > This patch eliminates the kvm_pv_eoi_features variable and simply uses > kvm_enabled() inside the enable_kvm_pv_eoi() compat function, so it > enables kvm_pv_eoi only if KVM is enabled. I believe this makes the > behavior of enable_kvm_pv_eoi() clearer and easier to understand. > > Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> > --- > Cc: kvm@vger.kernel.org > Cc: Michael S. Tsirkin <mst@redhat.com> > Cc: Gleb Natapov <gleb@redhat.com> > Cc: Marcelo Tosatti <mtosatti@redhat.com> > [snip] > void host_cpuid(uint32_t function, uint32_t count, > @@ -1343,13 +1337,15 @@ static int cpu_x86_parse_featurestr(x86_def_t *x86_cpu_def, char *features) > unsigned int i; > char *featurestr; /* Single 'key=value" string being parsed */ > /* Features to be added */ > - FeatureWordArray plus_features = { > - [FEAT_KVM] = kvm_default_features, > - }; > + FeatureWordArray plus_features = { 0 }; > /* Features to be removed */ > FeatureWordArray minus_features = { 0 }; > uint32_t numvalue; > > + if (kvm_enabled()) { > + plus_features[FEAT_KVM] = kvm_default_features; > + } While touching it please move setting defaults to cpu_x86_register() or cpu_x86_find_by_name() to so that cpu_x86_parse_featurestr() would deal only with custom settings. [snip]
On Fri, Jan 11, 2013 at 12:07:40AM +0100, Igor Mammedov wrote: [...] > > @@ -1343,13 +1337,15 @@ static int cpu_x86_parse_featurestr(x86_def_t *x86_cpu_def, char *features) > > unsigned int i; > > char *featurestr; /* Single 'key=value" string being parsed */ > > /* Features to be added */ > > - FeatureWordArray plus_features = { > > - [FEAT_KVM] = kvm_default_features, > > - }; > > + FeatureWordArray plus_features = { 0 }; > > /* Features to be removed */ > > FeatureWordArray minus_features = { 0 }; > > uint32_t numvalue; > > > > + if (kvm_enabled()) { > > + plus_features[FEAT_KVM] = kvm_default_features; > > + } > While touching it please move setting defaults to cpu_x86_register() or > cpu_x86_find_by_name() to so that cpu_x86_parse_featurestr() would deal only > with custom settings. OK, I will do it in the next version.
diff --git a/target-i386/cpu.c b/target-i386/cpu.c index e4dc370..57a22b7 100644 --- a/target-i386/cpu.c +++ b/target-i386/cpu.c @@ -206,22 +206,16 @@ typedef struct model_features_t { int check_cpuid = 0; int enforce_cpuid = 0; -#if defined(CONFIG_KVM) static uint32_t kvm_default_features = (1 << KVM_FEATURE_CLOCKSOURCE) | (1 << KVM_FEATURE_NOP_IO_DELAY) | (1 << KVM_FEATURE_CLOCKSOURCE2) | (1 << KVM_FEATURE_ASYNC_PF) | (1 << KVM_FEATURE_STEAL_TIME) | (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT); -static const uint32_t kvm_pv_eoi_features = (0x1 << KVM_FEATURE_PV_EOI); -#else -static uint32_t kvm_default_features = 0; -static const uint32_t kvm_pv_eoi_features = 0; -#endif void enable_kvm_pv_eoi(void) { - kvm_default_features |= kvm_pv_eoi_features; + kvm_default_features |= (1UL << KVM_FEATURE_PV_EOI); } void host_cpuid(uint32_t function, uint32_t count, @@ -1343,13 +1337,15 @@ static int cpu_x86_parse_featurestr(x86_def_t *x86_cpu_def, char *features) unsigned int i; char *featurestr; /* Single 'key=value" string being parsed */ /* Features to be added */ - FeatureWordArray plus_features = { - [FEAT_KVM] = kvm_default_features, - }; + FeatureWordArray plus_features = { 0 }; /* Features to be removed */ FeatureWordArray minus_features = { 0 }; uint32_t numvalue; + if (kvm_enabled()) { + plus_features[FEAT_KVM] = kvm_default_features; + } + add_flagname_to_bitmaps("hypervisor", plus_features); featurestr = features ? strtok(features, ",") : NULL;
This is a cleanup that tries to solve two small issues: - We don't need a separate kvm_pv_eoi_features variable just to keep a constant calculated at compile-time, and this style would require adding a separate variable (that's declared twice because of the CONFIG_KVM ifdef) for each feature that's going to be enabled/disable by machine-type compat code. - The pc-1.3 code is setting the kvm_pv_eoi flag on cpuid_kvm_features even when KVM is disabled at runtime. This small incosistency in the cpuid_kvm_features field isn't a problem today because cpuid_kvm_features is ignored by the TCG code, but it may cause unexpected problems later when refactoring the CPUID handling code. This patch eliminates the kvm_pv_eoi_features variable and simply uses kvm_enabled() inside the enable_kvm_pv_eoi() compat function, so it enables kvm_pv_eoi only if KVM is enabled. I believe this makes the behavior of enable_kvm_pv_eoi() clearer and easier to understand. Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> --- Cc: kvm@vger.kernel.org Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Changes v2: - Coding style fix Changes v3: - Eliminate #ifdef by using the fake KVM_FEATURE_PV_EOI #define Changes v4: - Check kvm_enabled() when actually using kvm_default_features - Eliminate Yet Another #ifdef by using the fake KVM_FEATURE_* #defines on kvm_default_features initialization --- target-i386/cpu.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-)