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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v2 11/30] xen/x86: Calculate maximum host and guest featuresets
All of this information will be used by the toolstack to make informed
levelling decisions for VMs, and by Xen to sanity check toolstack-provided
information.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
---
xen/arch/x86/cpuid.c | 152 ++++++++++++++++++++++++++++++++++++++++++++
xen/arch/x86/setup.c | 3 +
xen/include/asm-x86/cpuid.h | 17 +++++
3 files changed, 172 insertions(+)
diff --git a/xen/arch/x86/cpuid.c b/xen/arch/x86/cpuid.c
index 30a3392..1af0e6c 100644
--- a/xen/arch/x86/cpuid.c
+++ b/xen/arch/x86/cpuid.c
@@ -1,13 +1,165 @@
#include <xen/lib.h>
#include <asm/cpuid.h>
+#include <asm/hvm/hvm.h>
+#include <asm/hvm/vmx/vmcs.h>
+#include <asm/processor.h>
+
+#define COMMON_1D INIT_COMMON_FEATURES
const uint32_t known_features[] = INIT_KNOWN_FEATURES;
const uint32_t inverted_features[] = INIT_INVERTED_FEATURES;
+static const uint32_t pv_featuremask[] = INIT_PV_FEATURES;
+static const uint32_t hvm_shadow_featuremask[] = INIT_HVM_SHADOW_FEATURES;
+static const uint32_t hvm_hap_featuremask[] = INIT_HVM_HAP_FEATURES;
+
+uint32_t __read_mostly raw_featureset[FSCAPINTS];
+uint32_t __read_mostly host_featureset[FSCAPINTS];
+uint32_t __read_mostly pv_featureset[FSCAPINTS];
+uint32_t __read_mostly hvm_featureset[FSCAPINTS];
+
+static void sanitise_featureset(uint32_t *fs)
+{
+ unsigned int i;
+
+ for ( i = 0; i < FSCAPINTS; ++i )
+ {
+ /* Clamp to known mask. */
+ fs[i] &= known_features[i];
+ }
+
+ switch ( boot_cpu_data.x86_vendor )
+ {
+ case X86_VENDOR_INTEL:
+ /* Intel clears the common bits in e1d. */
+ fs[FEATURESET_e1d] &= ~COMMON_1D;
+ break;
+
+ case X86_VENDOR_AMD:
+ /* AMD duplicates the common bits between 1d and e1d. */
+ fs[FEATURESET_e1d] = ((fs[FEATURESET_1d] & COMMON_1D) |
+ (fs[FEATURESET_e1d] & ~COMMON_1D));
+ break;
+ }
+}
+
+static void calculate_raw_featureset(void)
+{
+ unsigned int i, max, tmp;
+
+ max = cpuid_eax(0);
+
+ if ( max >= 1 )
+ cpuid(0x1, &tmp, &tmp,
+ &raw_featureset[FEATURESET_1c],
+ &raw_featureset[FEATURESET_1d]);
+ if ( max >= 7 )
+ cpuid_count(0x7, 0, &tmp,
+ &raw_featureset[FEATURESET_7b0],
+ &raw_featureset[FEATURESET_7c0],
+ &tmp);
+ if ( max >= 0xd )
+ cpuid_count(0xd, 1,
+ &raw_featureset[FEATURESET_Da1],
+ &tmp, &tmp, &tmp);
+
+ max = cpuid_eax(0x80000000);
+ if ( max >= 0x80000001 )
+ cpuid(0x80000001, &tmp, &tmp,
+ &raw_featureset[FEATURESET_e1c],
+ &raw_featureset[FEATURESET_e1d]);
+ if ( max >= 0x80000007 )
+ cpuid(0x80000007, &tmp, &tmp, &tmp,
+ &raw_featureset[FEATURESET_e7d]);
+ if ( max >= 0x80000008 )
+ cpuid(0x80000008, &tmp,
+ &raw_featureset[FEATURESET_e8b],
+ &tmp, &tmp);
+
+ for ( i = 0; i < ARRAY_SIZE(raw_featureset); ++i )
+ raw_featureset[i] ^= inverted_features[i];
+}
+
+static void calculate_host_featureset(void)
+{
+ memcpy(host_featureset, boot_cpu_data.x86_capability,
+ sizeof(host_featureset));
+}
+
+static void calculate_pv_featureset(void)
+{
+ unsigned int i;
+
+ for ( i = 0; i < ARRAY_SIZE(pv_featureset); ++i )
+ pv_featureset[i] = host_featureset[i] & pv_featuremask[i];
+
+ /* Unconditionally claim to be able to set the hypervisor bit. */
+ __set_bit(X86_FEATURE_HYPERVISOR, pv_featureset);
+
+ sanitise_featureset(pv_featureset);
+}
+
+static void calculate_hvm_featureset(void)
+{
+ unsigned int i;
+ const uint32_t *hvm_featuremask;
+
+ if ( !hvm_enabled )
+ return;
+
+ hvm_featuremask = hvm_funcs.hap_supported ?
+ hvm_hap_featuremask : hvm_shadow_featuremask;
+
+ for ( i = 0; i < ARRAY_SIZE(hvm_featureset); ++i )
+ hvm_featureset[i] = host_featureset[i] & hvm_featuremask[i];
+
+ /* Unconditionally claim to be able to set the hypervisor bit. */
+ __set_bit(X86_FEATURE_HYPERVISOR, hvm_featureset);
+
+ /*
+ * On AMD, PV guests are entirely unable to use 'sysenter' as Xen runs in
+ * long mode (and init_amd() has cleared it out of host capabilities), but
+ * HVM guests are able if running in protected mode.
+ */
+ if ( (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) &&
+ test_bit(X86_FEATURE_SEP, raw_featureset) )
+ __set_bit(X86_FEATURE_SEP, hvm_featureset);
+
+ /*
+ * With VT-x, some features are only supported by Xen if dedicated
+ * hardware support is also available.
+ */
+ if ( cpu_has_vmx )
+ {
+ if ( !(vmx_vmexit_control & VM_EXIT_CLEAR_BNDCFGS) ||
+ !(vmx_vmentry_control & VM_ENTRY_LOAD_BNDCFGS) )
+ __clear_bit(X86_FEATURE_MPX, hvm_featureset);
+
+ if ( !cpu_has_vmx_xsaves )
+ __clear_bit(X86_FEATURE_XSAVES, hvm_featureset);
+
+ if ( !cpu_has_vmx_pcommit )
+ __clear_bit(X86_FEATURE_PCOMMIT, hvm_featureset);
+ }
+
+ sanitise_featureset(pv_featureset);
+}
+
+void calculate_featuresets(void)
+{
+ calculate_raw_featureset();
+ calculate_host_featureset();
+ calculate_pv_featureset();
+ calculate_hvm_featureset();
+}
+
static void __maybe_unused build_assertions(void)
{
BUILD_BUG_ON(ARRAY_SIZE(known_features) != FSCAPINTS);
BUILD_BUG_ON(ARRAY_SIZE(inverted_features) != FSCAPINTS);
+ BUILD_BUG_ON(ARRAY_SIZE(pv_featuremask) != FSCAPINTS);
+ BUILD_BUG_ON(ARRAY_SIZE(hvm_shadow_featuremask) != FSCAPINTS);
+ BUILD_BUG_ON(ARRAY_SIZE(hvm_hap_featuremask) != FSCAPINTS);
}
/*
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 76c7b0f..50e4e51 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -50,6 +50,7 @@
#include <asm/nmi.h>
#include <asm/alternative.h>
#include <asm/mc146818rtc.h>
+#include <asm/cpuid.h>
/* opt_nosmp: If true, secondary processors are ignored. */
static bool_t __initdata opt_nosmp;
@@ -1437,6 +1438,8 @@ void __init noreturn __start_xen(unsigned long mbi_p)
"Multiple initrd candidates, picking module #%u\n",
initrdidx);
+ calculate_featuresets();
+
/*
* Temporarily clear SMAP in CR4 to allow user-accesses in
construct_dom0().
* This saves a large number of corner cases interactions with
diff --git a/xen/include/asm-x86/cpuid.h b/xen/include/asm-x86/cpuid.h
index 341dbc1..18ba95b 100644
--- a/xen/include/asm-x86/cpuid.h
+++ b/xen/include/asm-x86/cpuid.h
@@ -5,12 +5,29 @@
#define FSCAPINTS FEATURESET_NR_ENTRIES
+#define FEATURESET_1d 0 /* 0x00000001.edx */
+#define FEATURESET_1c 1 /* 0x00000001.ecx */
+#define FEATURESET_e1d 2 /* 0x80000001.edx */
+#define FEATURESET_e1c 3 /* 0x80000001.ecx */
+#define FEATURESET_Da1 4 /* 0x0000000d:1.eax */
+#define FEATURESET_7b0 5 /* 0x00000007:0.ebx */
+#define FEATURESET_7c0 6 /* 0x00000007:0.ecx */
+#define FEATURESET_e7d 7 /* 0x80000007.edx */
+#define FEATURESET_e8b 8 /* 0x80000008.ebx */
+
#ifndef __ASSEMBLY__
#include <xen/types.h>
extern const uint32_t known_features[FSCAPINTS];
extern const uint32_t inverted_features[FSCAPINTS];
+extern uint32_t raw_featureset[FSCAPINTS];
+extern uint32_t host_featureset[FSCAPINTS];
+extern uint32_t pv_featureset[FSCAPINTS];
+extern uint32_t hvm_featureset[FSCAPINTS];
+
+void calculate_featuresets(void);
+
#endif /* __ASSEMBLY__ */
#endif /* !__X86_CPUID_H__ */
--
2.1.4
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