With accurate vendor information available, the shared bits can be sorted out
during recalculation, rather than at query time in the legacy cpuid path.
This means that:
* Duplication can be dropped from the automatically generated cpuid data.
* The toolstack need not worry about setting them appropriately.
* They can be dropped from the system maximum featuresets.
While editing gen-cpuid.py, reflow some comments which exceeded the expected
line length.
Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
---
CC: Jan Beulich <jbeul...@suse.com>
CC: Ian Jackson <ian.jack...@eu.citrix.com>
CC: Wei Liu <wei.l...@citrix.com>
---
tools/libxc/xc_cpuid_x86.c | 19 -------------------
xen/arch/x86/cpuid.c | 25 +++++--------------------
xen/tools/gen-cpuid.py | 29 ++++++++++-------------------
3 files changed, 15 insertions(+), 58 deletions(-)
diff --git a/tools/libxc/xc_cpuid_x86.c b/tools/libxc/xc_cpuid_x86.c
index 96d6025..918590f 100644
--- a/tools/libxc/xc_cpuid_x86.c
+++ b/tools/libxc/xc_cpuid_x86.c
@@ -41,7 +41,6 @@ enum {
#define DEF_MAX_BASE 0x0000000du
#define DEF_MAX_INTELEXT 0x80000008u
#define DEF_MAX_AMDEXT 0x8000001cu
-#define COMMON_1D CPUID_COMMON_1D_FEATURES
int xc_get_cpu_levelling_caps(xc_interface *xch, uint32_t *caps)
{
@@ -712,24 +711,6 @@ static void sanitise_featureset(struct cpuid_domain_info
*info)
disabled_features[i] &= ~dfs[i];
}
}
-
- switch ( info->vendor )
- {
- case VENDOR_INTEL:
- /* Intel clears the common bits in e1d. */
- info->featureset[featureword_of(X86_FEATURE_SYSCALL)] &= ~COMMON_1D;
- break;
-
- case VENDOR_AMD:
- /* AMD duplicates the common bits between 1d and e1d. */
- info->featureset[featureword_of(X86_FEATURE_SYSCALL)] =
- ((info->featureset[featureword_of(X86_FEATURE_FPU)] & COMMON_1D) |
- (info->featureset[featureword_of(X86_FEATURE_SYSCALL)] &
~COMMON_1D));
- break;
-
- default:
- break;
- }
}
int xc_cpuid_apply_policy(xc_interface *xch, domid_t domid,
diff --git a/xen/arch/x86/cpuid.c b/xen/arch/x86/cpuid.c
index 7926d0b..a27a8d6 100644
--- a/xen/arch/x86/cpuid.c
+++ b/xen/arch/x86/cpuid.c
@@ -67,18 +67,6 @@ static void sanitise_featureset(uint32_t *fs)
disabled_features[j] &= ~dfs[j];
}
}
-
- /*
- * Sort out shared bits. We are constructing a featureset which needs to
- * be applicable to a cross-vendor case. Intel strictly clears the common
- * bits in e1d, while AMD strictly duplicates them.
- *
- * We duplicate them here to be compatible with AMD while on Intel, and
- * rely on logic closer to the guest to make the featureset stricter if
- * emulating Intel.
- */
- fs[FEATURESET_e1d] = ((fs[FEATURESET_1d] & CPUID_COMMON_1D_FEATURES) |
- (fs[FEATURESET_e1d] & ~CPUID_COMMON_1D_FEATURES));
}
static void recalculate_xstate(struct cpuid_policy *p)
@@ -165,6 +153,8 @@ static void recalculate_xstate(struct cpuid_policy *p)
static void recalculate_common(struct cpuid_policy *p)
{
+ p->extd.e1d &= ~CPUID_COMMON_1D_FEATURES;
+
switch ( p->x86_vendor )
{
case X86_VENDOR_INTEL:
@@ -177,6 +167,8 @@ static void recalculate_common(struct cpuid_policy *p)
p->extd.vendor_ebx = p->basic.vendor_ebx;
p->extd.vendor_ecx = p->basic.vendor_ecx;
p->extd.vendor_edx = p->basic.vendor_edx;
+
+ p->extd.e1d |= p->basic._1d & CPUID_COMMON_1D_FEATURES;
break;
}
}
@@ -665,10 +657,6 @@ static void pv_cpuid(uint32_t leaf, uint32_t subleaf,
struct cpuid_leaf *res)
res->c = p->extd.e1c;
res->d = p->extd.e1d;
- /* If not emulating AMD, clear the duplicated features in e1d. */
- if ( p->x86_vendor != X86_VENDOR_AMD )
- res->d &= ~CPUID_COMMON_1D_FEATURES;
-
/*
* MTRR used to unconditionally leak into PV guests. They cannot MTRR
* infrastructure at all, and shouldn't be able to see the feature.
@@ -790,11 +778,8 @@ static void hvm_cpuid(uint32_t leaf, uint32_t subleaf,
struct cpuid_leaf *res)
res->c = p->extd.e1c;
res->d = p->extd.e1d;
- /* If not emulating AMD, clear the duplicated features in e1d. */
- if ( p->x86_vendor != X86_VENDOR_AMD )
- res->d &= ~CPUID_COMMON_1D_FEATURES;
/* fast-forward MSR_APIC_BASE.EN if it hasn't already been clobbered.
*/
- else if ( vlapic_hw_disabled(vcpu_vlapic(v)) )
+ if ( vlapic_hw_disabled(vcpu_vlapic(v)) )
res->d &= ~cpufeat_bit(X86_FEATURE_APIC);
/*
diff --git a/xen/tools/gen-cpuid.py b/xen/tools/gen-cpuid.py
index 6212e4f..5cab6db 100755
--- a/xen/tools/gen-cpuid.py
+++ b/xen/tools/gen-cpuid.py
@@ -129,16 +129,7 @@ def crunch_numbers(state):
common_1d = (FPU, VME, DE, PSE, TSC, MSR, PAE, MCE, CX8, APIC,
MTRR, PGE, MCA, CMOV, PAT, PSE36, MMX, FXSR)
- # All known features. Duplicate the common features in e1d
- e1d_base = SYSCALL & ~31
- state.known = featureset_to_uint32s(
- state.names.keys() + [ e1d_base + (x % 32) for x in common_1d ],
- nr_entries)
-
- # Fold common back into names
- for f in common_1d:
- state.names[e1d_base + (f % 32)] = "E1D_" + state.names[f]
-
+ state.known = featureset_to_uint32s(state.names.keys(), nr_entries)
state.common_1d = featureset_to_uint32s(common_1d, 1)[0]
state.special = featureset_to_uint32s(state.raw_special, nr_entries)
state.pv = featureset_to_uint32s(state.raw_pv, nr_entries)
@@ -248,13 +239,14 @@ def crunch_numbers(state):
# standard 3DNow in the earlier K6 processors.
_3DNOW: [_3DNOWEXT],
- # This is just the dependency between AVX512 and AVX2 of XSTATE
feature flags.
- # If want to use AVX512, AVX2 must be supported and enabled.
+ # This is just the dependency between AVX512 and AVX2 of XSTATE
+ # feature flags. If want to use AVX512, AVX2 must be supported and
+ # enabled.
AVX2: [AVX512F],
- # AVX512F is taken to mean hardware support for EVEX encoded
instructions,
- # 512bit registers, and the instructions themselves. All further
AVX512 features
- # are built on top of AVX512F
+ # AVX512F is taken to mean hardware support for EVEX encoded
+ # instructions, 512bit registers, and the instructions themselves. All
+ # further AVX512 features are built on top of AVX512F
AVX512F: [AVX512DQ, AVX512IFMA, AVX512PF, AVX512ER, AVX512CD,
AVX512BW, AVX512VL, AVX512VBMI, AVX512_4VNNIW,
AVX512_4FMAPS, AVX512_VPOPCNTDQ],
@@ -305,10 +297,9 @@ def crunch_numbers(state):
if name and name[0] in "0123456789":
name = "_" + name
- # Don't generate names for the duplicate features, or ones
- # fast-forwarded from other state
- if (name.startswith("E1D_") or
- name in ("APIC", "OSXSAVE", "OSPKE")):
+ # Don't generate names for features fast-forwarded from other
+ # state
+ if name in ("APIC", "OSXSAVE", "OSPKE"):
name = ""
names.append(name.lower())
--
2.1.4
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