| Message ID | 1357336872-7200-11-git-send-email-ehabkost@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Fri, Jan 04, 2013 at 08:01:11PM -0200, Eduardo Habkost wrote: > This will be necessary once kvm_check_features_against_host() starts > using KVM-specific definitions (so it won't compile anymore if > CONFIG_KVM is not set). > > Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> > --- > target-i386/cpu.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/target-i386/cpu.c b/target-i386/cpu.c > index 1c3c7e1..876b0f6 100644 > --- a/target-i386/cpu.c > +++ b/target-i386/cpu.c > @@ -936,6 +936,7 @@ static void kvm_cpu_fill_host(x86_def_t *x86_cpu_def) > #endif /* CONFIG_KVM */ > } > > +#ifdef CONFIG_KVM > static int unavailable_host_feature(struct model_features_t *f, uint32_t mask) > { > int i; > @@ -987,6 +988,7 @@ static int kvm_check_features_against_host(x86_def_t *guest_def) > } > return rv; > } > +#endif > > static void x86_cpuid_version_get_family(Object *obj, Visitor *v, void *opaque, > const char *name, Error **errp) > @@ -1410,10 +1412,12 @@ static int cpu_x86_parse_featurestr(x86_def_t *x86_cpu_def, char *features) > x86_cpu_def->kvm_features &= ~minus_kvm_features; > x86_cpu_def->svm_features &= ~minus_svm_features; > x86_cpu_def->cpuid_7_0_ebx_features &= ~minus_7_0_ebx_features; > +#ifdef CONFIG_KVM > if (check_cpuid && kvm_enabled()) { > if (kvm_check_features_against_host(x86_cpu_def) && enforce_cpuid) > goto error; > } > +#endif Provide kvm_check_features_against_host() stub if !CONFIG_KVM and drop ifdef here. > return 0; > > error: > -- > 1.7.11.7 > -- Gleb.
On Sun, Jan 06, 2013 at 04:27:19PM +0200, Gleb Natapov wrote: > On Fri, Jan 04, 2013 at 08:01:11PM -0200, Eduardo Habkost wrote: > > This will be necessary once kvm_check_features_against_host() starts > > using KVM-specific definitions (so it won't compile anymore if > > CONFIG_KVM is not set). > > > > Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> > > --- > > target-i386/cpu.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/target-i386/cpu.c b/target-i386/cpu.c > > index 1c3c7e1..876b0f6 100644 > > --- a/target-i386/cpu.c > > +++ b/target-i386/cpu.c > > @@ -936,6 +936,7 @@ static void kvm_cpu_fill_host(x86_def_t *x86_cpu_def) > > #endif /* CONFIG_KVM */ > > } > > > > +#ifdef CONFIG_KVM > > static int unavailable_host_feature(struct model_features_t *f, uint32_t mask) > > { > > int i; > > @@ -987,6 +988,7 @@ static int kvm_check_features_against_host(x86_def_t *guest_def) > > } > > return rv; > > } > > +#endif > > > > static void x86_cpuid_version_get_family(Object *obj, Visitor *v, void *opaque, > > const char *name, Error **errp) > > @@ -1410,10 +1412,12 @@ static int cpu_x86_parse_featurestr(x86_def_t *x86_cpu_def, char *features) > > x86_cpu_def->kvm_features &= ~minus_kvm_features; > > x86_cpu_def->svm_features &= ~minus_svm_features; > > x86_cpu_def->cpuid_7_0_ebx_features &= ~minus_7_0_ebx_features; > > +#ifdef CONFIG_KVM > > if (check_cpuid && kvm_enabled()) { > > if (kvm_check_features_against_host(x86_cpu_def) && enforce_cpuid) > > goto error; > > } > > +#endif > Provide kvm_check_features_against_host() stub if !CONFIG_KVM and drop > ifdef here. I will do. Igor probably will have to change his "target-i386: move kvm_check_features_against_host() check to realize time" patch to use the same approach, too.
On Mon, 7 Jan 2013 10:00:09 -0200 Eduardo Habkost <ehabkost@redhat.com> wrote: > On Sun, Jan 06, 2013 at 04:27:19PM +0200, Gleb Natapov wrote: > > On Fri, Jan 04, 2013 at 08:01:11PM -0200, Eduardo Habkost wrote: > > > This will be necessary once kvm_check_features_against_host() starts > > > using KVM-specific definitions (so it won't compile anymore if > > > CONFIG_KVM is not set). > > > > > > Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> > > > --- > > > target-i386/cpu.c | 4 ++++ > > > 1 file changed, 4 insertions(+) > > > > > > diff --git a/target-i386/cpu.c b/target-i386/cpu.c > > > index 1c3c7e1..876b0f6 100644 > > > --- a/target-i386/cpu.c > > > +++ b/target-i386/cpu.c > > > @@ -936,6 +936,7 @@ static void kvm_cpu_fill_host(x86_def_t *x86_cpu_def) > > > #endif /* CONFIG_KVM */ > > > } > > > > > > +#ifdef CONFIG_KVM > > > static int unavailable_host_feature(struct model_features_t *f, uint32_t mask) > > > { > > > int i; > > > @@ -987,6 +988,7 @@ static int kvm_check_features_against_host(x86_def_t *guest_def) > > > } > > > return rv; > > > } > > > +#endif > > > > > > static void x86_cpuid_version_get_family(Object *obj, Visitor *v, void *opaque, > > > const char *name, Error **errp) > > > @@ -1410,10 +1412,12 @@ static int cpu_x86_parse_featurestr(x86_def_t *x86_cpu_def, char *features) > > > x86_cpu_def->kvm_features &= ~minus_kvm_features; > > > x86_cpu_def->svm_features &= ~minus_svm_features; > > > x86_cpu_def->cpuid_7_0_ebx_features &= ~minus_7_0_ebx_features; > > > +#ifdef CONFIG_KVM > > > if (check_cpuid && kvm_enabled()) { > > > if (kvm_check_features_against_host(x86_cpu_def) && enforce_cpuid) > > > goto error; > > > } > > > +#endif > > Provide kvm_check_features_against_host() stub if !CONFIG_KVM and drop > > ifdef here. > > I will do. Igor probably will have to change his "target-i386: move > kvm_check_features_against_host() check to realize time" patch to use > the same approach, too. Gleb, Why do stub here? As result we will be adding more ifdef-s just in other places. Currently kvm_cpu_fill_host(), unavailable_host_feature() and kvm_check_features_against_host() are bundled together in cpu.c so we could instead ifdef whole block. Like here: http://www.mail-archive.com/qemu-devel@nongnu.org/msg146536.html For me code looks more readable with ifdef here, if we have stub, a reader would have to look at kvm_check_features_against_host() body to see if it does anything. > > -- > Eduardo >
On Mon, Jan 07, 2013 at 02:15:14PM +0100, Igor Mammedov wrote: > On Mon, 7 Jan 2013 10:00:09 -0200 > Eduardo Habkost <ehabkost@redhat.com> wrote: > > > On Sun, Jan 06, 2013 at 04:27:19PM +0200, Gleb Natapov wrote: > > > On Fri, Jan 04, 2013 at 08:01:11PM -0200, Eduardo Habkost wrote: > > > > This will be necessary once kvm_check_features_against_host() starts > > > > using KVM-specific definitions (so it won't compile anymore if > > > > CONFIG_KVM is not set). > > > > > > > > Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> > > > > --- > > > > target-i386/cpu.c | 4 ++++ > > > > 1 file changed, 4 insertions(+) > > > > > > > > diff --git a/target-i386/cpu.c b/target-i386/cpu.c > > > > index 1c3c7e1..876b0f6 100644 > > > > --- a/target-i386/cpu.c > > > > +++ b/target-i386/cpu.c > > > > @@ -936,6 +936,7 @@ static void kvm_cpu_fill_host(x86_def_t *x86_cpu_def) > > > > #endif /* CONFIG_KVM */ > > > > } > > > > > > > > +#ifdef CONFIG_KVM > > > > static int unavailable_host_feature(struct model_features_t *f, uint32_t mask) > > > > { > > > > int i; > > > > @@ -987,6 +988,7 @@ static int kvm_check_features_against_host(x86_def_t *guest_def) > > > > } > > > > return rv; > > > > } > > > > +#endif > > > > > > > > static void x86_cpuid_version_get_family(Object *obj, Visitor *v, void *opaque, > > > > const char *name, Error **errp) > > > > @@ -1410,10 +1412,12 @@ static int cpu_x86_parse_featurestr(x86_def_t *x86_cpu_def, char *features) > > > > x86_cpu_def->kvm_features &= ~minus_kvm_features; > > > > x86_cpu_def->svm_features &= ~minus_svm_features; > > > > x86_cpu_def->cpuid_7_0_ebx_features &= ~minus_7_0_ebx_features; > > > > +#ifdef CONFIG_KVM > > > > if (check_cpuid && kvm_enabled()) { > > > > if (kvm_check_features_against_host(x86_cpu_def) && enforce_cpuid) > > > > goto error; > > > > } > > > > +#endif > > > Provide kvm_check_features_against_host() stub if !CONFIG_KVM and drop > > > ifdef here. > > > > I will do. Igor probably will have to change his "target-i386: move > > kvm_check_features_against_host() check to realize time" patch to use > > the same approach, too. > > > Gleb, > > Why do stub here? As result we will be adding more ifdef-s just in other > places. Currently kvm_cpu_fill_host(), unavailable_host_feature() and Why will we be adding more ifdef-s in other places? > kvm_check_features_against_host() are bundled together in cpu.c so we could > instead ifdef whole block. Like here: > http://www.mail-archive.com/qemu-devel@nongnu.org/msg146536.html > That's fine, but you can avoid things like: if (kvm_enabled() && name && strcmp(name, "host") == 0) { +#ifdef CONFIG_KVM kvm_cpu_fill_host(x86_cpu_def); +#endif in your patch by providing stub for kvm_cpu_fill_host() for !CONFIG_KVM case. This is common practice really. Avoid ifdefs in the code. > For me code looks more readable with ifdef here, if we have stub, a reader > would have to look at kvm_check_features_against_host() body to see if it does > anything. > If reader cares about kvm it has to anyway. If he does not, there is friendly kvm_enabled() (which is stub in case of !CONFIG_KVM BTW) to tell him that he does not care. No need additional ifdef there. -- Gleb.
On Mon, Jan 07, 2013 at 02:15:14PM +0100, Igor Mammedov wrote: > On Mon, 7 Jan 2013 10:00:09 -0200 > Eduardo Habkost <ehabkost@redhat.com> wrote: > > > On Sun, Jan 06, 2013 at 04:27:19PM +0200, Gleb Natapov wrote: > > > On Fri, Jan 04, 2013 at 08:01:11PM -0200, Eduardo Habkost wrote: > > > > This will be necessary once kvm_check_features_against_host() starts > > > > using KVM-specific definitions (so it won't compile anymore if > > > > CONFIG_KVM is not set). > > > > > > > > Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> > > > > --- > > > > target-i386/cpu.c | 4 ++++ > > > > 1 file changed, 4 insertions(+) > > > > > > > > diff --git a/target-i386/cpu.c b/target-i386/cpu.c > > > > index 1c3c7e1..876b0f6 100644 > > > > --- a/target-i386/cpu.c > > > > +++ b/target-i386/cpu.c > > > > @@ -936,6 +936,7 @@ static void kvm_cpu_fill_host(x86_def_t *x86_cpu_def) > > > > #endif /* CONFIG_KVM */ > > > > } > > > > > > > > +#ifdef CONFIG_KVM > > > > static int unavailable_host_feature(struct model_features_t *f, uint32_t mask) > > > > { > > > > int i; > > > > @@ -987,6 +988,7 @@ static int kvm_check_features_against_host(x86_def_t *guest_def) > > > > } > > > > return rv; > > > > } > > > > +#endif > > > > > > > > static void x86_cpuid_version_get_family(Object *obj, Visitor *v, void *opaque, > > > > const char *name, Error **errp) > > > > @@ -1410,10 +1412,12 @@ static int cpu_x86_parse_featurestr(x86_def_t *x86_cpu_def, char *features) > > > > x86_cpu_def->kvm_features &= ~minus_kvm_features; > > > > x86_cpu_def->svm_features &= ~minus_svm_features; > > > > x86_cpu_def->cpuid_7_0_ebx_features &= ~minus_7_0_ebx_features; > > > > +#ifdef CONFIG_KVM > > > > if (check_cpuid && kvm_enabled()) { > > > > if (kvm_check_features_against_host(x86_cpu_def) && enforce_cpuid) > > > > goto error; > > > > } > > > > +#endif > > > Provide kvm_check_features_against_host() stub if !CONFIG_KVM and drop > > > ifdef here. > > > > I will do. Igor probably will have to change his "target-i386: move > > kvm_check_features_against_host() check to realize time" patch to use > > the same approach, too. > > > Gleb, > > Why do stub here? As result we will be adding more ifdef-s just in other > places. Currently kvm_cpu_fill_host(), unavailable_host_feature() and > kvm_check_features_against_host() are bundled together in cpu.c so we could > instead ifdef whole block. Like here: > http://www.mail-archive.com/qemu-devel@nongnu.org/msg146536.html > > For me code looks more readable with ifdef here, if we have stub, a reader > would have to look at kvm_check_features_against_host() body to see if it does > anything. If CONFIG_KVM is not set, kvm_enabled() is always zero, so the function would never be called, so I find the ifdef-less code more readable and obvious. What I don't know is if we should do this: #ifdef CONFIG_KVM static int kvm_check_features_against_host(...) { /* real implementation here */ } static int kvm_do_something_else(...) { /* real implementation here */ } /* Other kvm_* functions here */ #else static int kvm_check_features_against_host(...) { } static int kvm_do_something_else(...) { } /* Other kvm_* stubs here */ #endif /* CONFIG_KVM */ Or this: static int kvm_check_features_against_host(...) { #ifdef CONFIG_KVM /* real implementation here */ #endif /* CONFIG_KVM */ } static int kvm_do_something_else(...) { #ifdef CONFIG_KVM /* real implementation here */ #endif /* CONFIG_KVM */ } I believe the latter is better, but based on Gleb's comments about enable_kvm_pv_eoi(), he seems to prefer the former.
On Mon, 7 Jan 2013 15:30:26 +0200 Gleb Natapov <gleb@redhat.com> wrote: > On Mon, Jan 07, 2013 at 02:15:14PM +0100, Igor Mammedov wrote: > > On Mon, 7 Jan 2013 10:00:09 -0200 > > Eduardo Habkost <ehabkost@redhat.com> wrote: > > > > > On Sun, Jan 06, 2013 at 04:27:19PM +0200, Gleb Natapov wrote: > > > > On Fri, Jan 04, 2013 at 08:01:11PM -0200, Eduardo Habkost wrote: > > > > > This will be necessary once kvm_check_features_against_host() starts > > > > > using KVM-specific definitions (so it won't compile anymore if > > > > > CONFIG_KVM is not set). > > > > > > > > > > Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> > > > > > --- > > > > > target-i386/cpu.c | 4 ++++ > > > > > 1 file changed, 4 insertions(+) > > > > > > > > > > diff --git a/target-i386/cpu.c b/target-i386/cpu.c > > > > > index 1c3c7e1..876b0f6 100644 > > > > > --- a/target-i386/cpu.c > > > > > +++ b/target-i386/cpu.c > > > > > @@ -936,6 +936,7 @@ static void kvm_cpu_fill_host(x86_def_t *x86_cpu_def) > > > > > #endif /* CONFIG_KVM */ > > > > > } > > > > > > > > > > +#ifdef CONFIG_KVM > > > > > static int unavailable_host_feature(struct model_features_t *f, uint32_t mask) > > > > > { > > > > > int i; > > > > > @@ -987,6 +988,7 @@ static int kvm_check_features_against_host(x86_def_t *guest_def) > > > > > } > > > > > return rv; > > > > > } > > > > > +#endif > > > > > > > > > > static void x86_cpuid_version_get_family(Object *obj, Visitor *v, void *opaque, > > > > > const char *name, Error **errp) > > > > > @@ -1410,10 +1412,12 @@ static int cpu_x86_parse_featurestr(x86_def_t *x86_cpu_def, char *features) > > > > > x86_cpu_def->kvm_features &= ~minus_kvm_features; > > > > > x86_cpu_def->svm_features &= ~minus_svm_features; > > > > > x86_cpu_def->cpuid_7_0_ebx_features &= ~minus_7_0_ebx_features; > > > > > +#ifdef CONFIG_KVM > > > > > if (check_cpuid && kvm_enabled()) { > > > > > if (kvm_check_features_against_host(x86_cpu_def) && enforce_cpuid) > > > > > goto error; > > > > > } > > > > > +#endif > > > > Provide kvm_check_features_against_host() stub if !CONFIG_KVM and drop > > > > ifdef here. > > > > > > I will do. Igor probably will have to change his "target-i386: move > > > kvm_check_features_against_host() check to realize time" patch to use > > > the same approach, too. > > > > > > Gleb, > > > > Why do stub here? As result we will be adding more ifdef-s just in other > > places. Currently kvm_cpu_fill_host(), unavailable_host_feature() and > Why will we be adding more ifdef-s in other places? unavailable_host_feature() is being ifdef-ed above > > > kvm_check_features_against_host() are bundled together in cpu.c so we could > > instead ifdef whole block. Like here: > > http://www.mail-archive.com/qemu-devel@nongnu.org/msg146536.html > > > That's fine, but you can avoid things like: > > if (kvm_enabled() && name && strcmp(name, "host") == 0) { > +#ifdef CONFIG_KVM > kvm_cpu_fill_host(x86_cpu_def); > +#endif > > in your patch by providing stub for kvm_cpu_fill_host() for !CONFIG_KVM > case. This is common practice really. Avoid ifdefs in the code. This ifdef could be eliminated later when cpus are converted into sub-classes. Then we would put host subclass close to kvm_cpu_fill_host inside of the same ifdef. that would leave ifdef around kvm_check_features_against_host() in cpu_x86_parse_featurestr(). > > > For me code looks more readable with ifdef here, if we have stub, a reader > > would have to look at kvm_check_features_against_host() body to see if it does > > anything. > > > If reader cares about kvm it has to anyway. If he does not, there is > friendly kvm_enabled() (which is stub in case of !CONFIG_KVM BTW) to > tell him that he does not care. No need additional ifdef there. both ways would work, but if stubs are preferred style then there is no point arguing. > > -- > Gleb.
diff --git a/target-i386/cpu.c b/target-i386/cpu.c index 1c3c7e1..876b0f6 100644 --- a/target-i386/cpu.c +++ b/target-i386/cpu.c @@ -936,6 +936,7 @@ static void kvm_cpu_fill_host(x86_def_t *x86_cpu_def) #endif /* CONFIG_KVM */ } +#ifdef CONFIG_KVM static int unavailable_host_feature(struct model_features_t *f, uint32_t mask) { int i; @@ -987,6 +988,7 @@ static int kvm_check_features_against_host(x86_def_t *guest_def) } return rv; } +#endif static void x86_cpuid_version_get_family(Object *obj, Visitor *v, void *opaque, const char *name, Error **errp) @@ -1410,10 +1412,12 @@ static int cpu_x86_parse_featurestr(x86_def_t *x86_cpu_def, char *features) x86_cpu_def->kvm_features &= ~minus_kvm_features; x86_cpu_def->svm_features &= ~minus_svm_features; x86_cpu_def->cpuid_7_0_ebx_features &= ~minus_7_0_ebx_features; +#ifdef CONFIG_KVM if (check_cpuid && kvm_enabled()) { if (kvm_check_features_against_host(x86_cpu_def) && enforce_cpuid) goto error; } +#endif return 0; error:
This will be necessary once kvm_check_features_against_host() starts using KVM-specific definitions (so it won't compile anymore if CONFIG_KVM is not set). Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> --- target-i386/cpu.c | 4 ++++ 1 file changed, 4 insertions(+)