| Message ID | 20210607124141.24767-1-andrew.cooper3@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | x86/cpuid: Drop special_features[] | expand |
On 07.06.2021 14:41, Andrew Cooper wrote: > While the ! annotation is useful to indicate that something special is > happening, an array of bits is not. Drop it, to prevent mistakes. > > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
On 07.06.2021 14:41, Andrew Cooper wrote: > While the ! annotation is useful to indicate that something special is > happening, an array of bits is not. Drop it, to prevent mistakes. > > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> > --- > CC: Jan Beulich <JBeulich@suse.com> > CC: Roger Pau Monné <roger.pau@citrix.com> > CC: Wei Liu <wl@xen.org> > --- > xen/arch/x86/cpuid.c | 2 -- > xen/include/asm-x86/cpuid.h | 1 - > xen/tools/gen-cpuid.py | 3 --- > 3 files changed, 6 deletions(-) As osstest points out this didn't go quite far enough, or too far: Either XC_FEATUREMASK_SPECIAL also needs dropping (including its uses in libxenguest and xen-cpuid) or, considering exposing this information via xen-cpuid isn't entirely without purpose, the script part of the original change needs undoing or making conditional e.g. upon __XEN__. Jan
On 08/06/2021 07:18, Jan Beulich wrote: > On 07.06.2021 14:41, Andrew Cooper wrote: >> While the ! annotation is useful to indicate that something special is >> happening, an array of bits is not. Drop it, to prevent mistakes. >> >> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> >> --- >> CC: Jan Beulich <JBeulich@suse.com> >> CC: Roger Pau Monné <roger.pau@citrix.com> >> CC: Wei Liu <wl@xen.org> >> --- >> xen/arch/x86/cpuid.c | 2 -- >> xen/include/asm-x86/cpuid.h | 1 - >> xen/tools/gen-cpuid.py | 3 --- >> 3 files changed, 6 deletions(-) > As osstest points out this didn't go quite far enough, or too far: > Either XC_FEATUREMASK_SPECIAL also needs dropping (including its uses > in libxenguest and xen-cpuid) or, considering exposing this > information via xen-cpuid isn't entirely without purpose, the script > part of the original change needs undoing or making conditional e.g. > upon __XEN__. Yes - Gitlab CI didn't spot, because there is a different breakage from PV32 blocking things. I think I'll reinstate the gen-cpuid.py hunks because having xen-cpuid print out the bits when asked is helpful. ~Andrew
On 08.06.2021 10:46, Andrew Cooper wrote: > On 08/06/2021 07:18, Jan Beulich wrote: >> On 07.06.2021 14:41, Andrew Cooper wrote: >>> While the ! annotation is useful to indicate that something special is >>> happening, an array of bits is not. Drop it, to prevent mistakes. >>> >>> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> >>> --- >>> CC: Jan Beulich <JBeulich@suse.com> >>> CC: Roger Pau Monné <roger.pau@citrix.com> >>> CC: Wei Liu <wl@xen.org> >>> --- >>> xen/arch/x86/cpuid.c | 2 -- >>> xen/include/asm-x86/cpuid.h | 1 - >>> xen/tools/gen-cpuid.py | 3 --- >>> 3 files changed, 6 deletions(-) >> As osstest points out this didn't go quite far enough, or too far: >> Either XC_FEATUREMASK_SPECIAL also needs dropping (including its uses >> in libxenguest and xen-cpuid) or, considering exposing this >> information via xen-cpuid isn't entirely without purpose, the script >> part of the original change needs undoing or making conditional e.g. >> upon __XEN__. > > Yes - Gitlab CI didn't spot, because there is a different breakage from > PV32 blocking things. Oh, what further problem do we have? What I can see there (picking a random build log) is the failure from the change here ... > I think I'll reinstate the gen-cpuid.py hunks because having xen-cpuid > print out the bits when asked is helpful. And maybe put the #define inside "#ifndef __XEN__" then? Jan
diff --git a/xen/arch/x86/cpuid.c b/xen/arch/x86/cpuid.c index 958caf35da..2079a30ae4 100644 --- a/xen/arch/x86/cpuid.c +++ b/xen/arch/x86/cpuid.c @@ -14,7 +14,6 @@ #include <asm/xstate.h> const uint32_t known_features[] = INIT_KNOWN_FEATURES; -const uint32_t special_features[] = INIT_SPECIAL_FEATURES; static const uint32_t __initconst pv_max_featuremask[] = INIT_PV_MAX_FEATURES; static const uint32_t hvm_shadow_max_featuremask[] = INIT_HVM_SHADOW_MAX_FEATURES; @@ -1132,7 +1131,6 @@ void guest_cpuid(const struct vcpu *v, uint32_t leaf, static void __init __maybe_unused build_assertions(void) { BUILD_BUG_ON(ARRAY_SIZE(known_features) != FSCAPINTS); - BUILD_BUG_ON(ARRAY_SIZE(special_features) != FSCAPINTS); BUILD_BUG_ON(ARRAY_SIZE(pv_max_featuremask) != FSCAPINTS); BUILD_BUG_ON(ARRAY_SIZE(hvm_shadow_max_featuremask) != FSCAPINTS); BUILD_BUG_ON(ARRAY_SIZE(hvm_hap_max_featuremask) != FSCAPINTS); diff --git a/xen/include/asm-x86/cpuid.h b/xen/include/asm-x86/cpuid.h index 7baf6c9628..46904061d0 100644 --- a/xen/include/asm-x86/cpuid.h +++ b/xen/include/asm-x86/cpuid.h @@ -14,7 +14,6 @@ #include <public/sysctl.h> extern const uint32_t known_features[FSCAPINTS]; -extern const uint32_t special_features[FSCAPINTS]; void init_guest_cpuid(void); diff --git a/xen/tools/gen-cpuid.py b/xen/tools/gen-cpuid.py index b953648b65..c6b5056a8d 100755 --- a/xen/tools/gen-cpuid.py +++ b/xen/tools/gen-cpuid.py @@ -362,8 +362,6 @@ def write_results(state): #define INIT_KNOWN_FEATURES { \\\n%s\n} -#define INIT_SPECIAL_FEATURES { \\\n%s\n} - #define INIT_PV_DEF_FEATURES { \\\n%s\n} #define INIT_PV_MAX_FEATURES { \\\n%s\n} @@ -384,7 +382,6 @@ def write_results(state): """ % (state.nr_entries, next(featureset_to_uint32s(state.common_1d, 1)), format_uint32s(state, state.names.keys(), 4), - format_uint32s(state, state.raw['!'], 4), format_uint32s(state, state.pv_def, 4), format_uint32s(state, state.pv_max, 4), format_uint32s(state, state.hvm_shadow_def, 4),
While the ! annotation is useful to indicate that something special is happening, an array of bits is not. Drop it, to prevent mistakes. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> --- CC: Jan Beulich <JBeulich@suse.com> CC: Roger Pau Monné <roger.pau@citrix.com> CC: Wei Liu <wl@xen.org> --- xen/arch/x86/cpuid.c | 2 -- xen/include/asm-x86/cpuid.h | 1 - xen/tools/gen-cpuid.py | 3 --- 3 files changed, 6 deletions(-)