| Message ID | 1358456378-29248-3-git-send-email-ehabkost@redhat.com |
|---|---|
| State | New |
| Headers | show |
Am 17.01.2013 21:59, schrieb Eduardo Habkost: > 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> Fine with me if KVM folks agree. Andreas > --- > 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 > > Changes v5: > - Rebase and move the kvm_enabled() check to cpu_x86_register() > --- > target-i386/cpu.c | 12 ++++-------- > 1 file changed, 4 insertions(+), 8 deletions(-) > > diff --git a/target-i386/cpu.c b/target-i386/cpu.c > index 333745b..754eb6f 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, > @@ -1602,7 +1596,9 @@ int cpu_x86_register(X86CPU *cpu, const char *cpu_model) > goto out; > } > > - def->kvm_features |= kvm_default_features; > + if (kvm_enabled()) { > + def->kvm_features |= kvm_default_features; > + } > def->ext_features |= CPUID_EXT_HYPERVISOR; > > if (cpu_x86_parse_featurestr(def, features) < 0) { >
On Fri, Jan 18, 2013 at 11:58:34AM +0100, Andreas Färber wrote: > Am 17.01.2013 21:59, schrieb Eduardo Habkost: > > 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> > > Fine with me if KVM folks agree. > Acked-by: Gleb Natapov <gleb@redhat.com> > Andreas > > > --- > > 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 > > > > Changes v5: > > - Rebase and move the kvm_enabled() check to cpu_x86_register() > > --- > > target-i386/cpu.c | 12 ++++-------- > > 1 file changed, 4 insertions(+), 8 deletions(-) > > > > diff --git a/target-i386/cpu.c b/target-i386/cpu.c > > index 333745b..754eb6f 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, > > @@ -1602,7 +1596,9 @@ int cpu_x86_register(X86CPU *cpu, const char *cpu_model) > > goto out; > > } > > > > - def->kvm_features |= kvm_default_features; > > + if (kvm_enabled()) { > > + def->kvm_features |= kvm_default_features; > > + } > > def->ext_features |= CPUID_EXT_HYPERVISOR; > > > > if (cpu_x86_parse_featurestr(def, features) < 0) { > > > > > -- > SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany > GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg -- Gleb.
On Thu, Jan 17, 2013 at 06:59:28PM -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> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/target-i386/cpu.c b/target-i386/cpu.c index 333745b..754eb6f 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, @@ -1602,7 +1596,9 @@ int cpu_x86_register(X86CPU *cpu, const char *cpu_model) goto out; } - def->kvm_features |= kvm_default_features; + if (kvm_enabled()) { + def->kvm_features |= kvm_default_features; + } def->ext_features |= CPUID_EXT_HYPERVISOR; if (cpu_x86_parse_featurestr(def, features) < 0) {
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 Changes v5: - Rebase and move the kvm_enabled() check to cpu_x86_register() --- target-i386/cpu.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-)