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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen master] x86/cpuid: Move all leaf 7 handling into guest_cpuid()
commit bc54ec1aeeab40eae00ed68316b64d4f1984290d
Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Wed Jan 11 11:59:02 2017 +0000
Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Wed Jan 11 11:59:02 2017 +0000
x86/cpuid: Move all leaf 7 handling into guest_cpuid()
All per-domain policy data concerning leaf 7 is accurate. Handle it all in
guest_cpuid() by reading out of the raw array block, and introduing a
dynamic
adjustment for OSPKE.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
xen/arch/x86/cpuid.c | 46 +++++++++++++++++++++++++++++++++++++++++++--
xen/arch/x86/hvm/hvm.c | 17 ++++-------------
xen/arch/x86/traps.c | 28 ++++-----------------------
xen/include/asm-x86/cpuid.h | 2 ++
4 files changed, 54 insertions(+), 39 deletions(-)
diff --git a/xen/arch/x86/cpuid.c b/xen/arch/x86/cpuid.c
index c6552b7..faf745b 100644
--- a/xen/arch/x86/cpuid.c
+++ b/xen/arch/x86/cpuid.c
@@ -362,6 +362,7 @@ void guest_cpuid(const struct vcpu *v, uint32_t leaf,
* First pass:
* - Perform max_leaf/subleaf calculations. Out-of-range leaves return
* all zeros, following the AMD model.
+ * - Fill in *res for leaves no longer handled on the legacy path.
* - Dispatch the virtualised leaves to their respective handlers.
*/
switch ( leaf )
@@ -375,12 +376,18 @@ void guest_cpuid(const struct vcpu *v, uint32_t leaf,
case 0x7:
if ( subleaf > p->feat.max_subleaf )
return;
+
+ BUG_ON(subleaf >= ARRAY_SIZE(p->feat.raw));
+ *res = p->feat.raw[subleaf];
break;
case XSTATE_CPUID:
if ( subleaf > ARRAY_SIZE(p->xstate.raw) )
return;
- break;
+
+ /* Fallthrough. */
+ default:
+ goto legacy;
}
break;
@@ -400,12 +407,47 @@ void guest_cpuid(const struct vcpu *v, uint32_t leaf,
case 0x80000000 ... 0x80000000 + CPUID_GUEST_NR_EXTD - 1:
if ( leaf > p->extd.max_leaf )
return;
- break;
+ goto legacy;
default:
return;
}
+ /*
+ * Skip dynamic adjustments if we are in the wrong context.
+ *
+ * All dynamic adjustments depends on current register state, which will
+ * be stale if the vcpu is running elsewhere. It is simpler, quicker, and
+ * more reliable for the caller to do nothing (consistently) than to hand
+ * back stale data which it can't use safely.
+ */
+ if ( v != current )
+ return;
+
+ /*
+ * Second pass:
+ * - Dynamic adjustments
+ */
+ switch ( leaf )
+ {
+ case 0x7:
+ switch ( subleaf )
+ {
+ case 0:
+ /* OSPKE clear in policy. Fast-forward CR4 back in. */
+ if ( (is_pv_domain(d)
+ ? v->arch.pv_vcpu.ctrlreg[4]
+ : v->arch.hvm_vcpu.guest_cr[4]) & X86_CR4_PKE )
+ res->c |= cpufeat_mask(X86_FEATURE_OSPKE);
+ break;
+ }
+ break;
+ }
+
+ /* Done. */
+ return;
+
+ legacy:
/* {hvm,pv}_cpuid() have this expectation. */
ASSERT(v == current);
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index e2af179..472f10f 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3355,19 +3355,6 @@ void hvm_cpuid(unsigned int input, unsigned int *eax,
unsigned int *ebx,
break;
- case 0x7:
- if ( count == 0 )
- {
- *ebx = p->feat._7b0;
- *ecx = p->feat._7c0;
- *edx = p->feat._7d0;
-
- /* OSPKE clear in policy. Fast-forward CR4 back in. */
- if ( v->arch.hvm_vcpu.guest_cr[4] & X86_CR4_PKE )
- *ecx |= cpufeat_mask(X86_FEATURE_OSPKE);
- }
- break;
-
case 0xb:
/* Fix the x2APIC identifier. */
*edx = v->vcpu_id * 2;
@@ -3544,6 +3531,10 @@ void hvm_cpuid(unsigned int input, unsigned int *eax,
unsigned int *ebx,
else
*eax = 0;
break;
+
+ case 0x7:
+ ASSERT_UNREACHABLE();
+ /* Now handled in guest_cpuid(). */
}
}
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 6e08efe..47d313a 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -1179,30 +1179,6 @@ void pv_cpuid(struct cpu_user_regs *regs)
}
break;
- case 0x00000007:
- if ( subleaf == 0 )
- {
- b = p->feat._7b0;
- c = p->feat._7c0;
- d = p->feat._7d0;
-
- if ( !is_pvh_domain(currd) )
- {
- /*
- * Delete the PVH condition when HVMLite formally replaces PVH,
- * and HVM guests no longer enter a PV codepath.
- */
-
- /* OSPKE clear in policy. Fast-forward CR4 back in. */
- if ( curr->arch.pv_vcpu.ctrlreg[4] & X86_CR4_PKE )
- c |= cpufeat_mask(X86_FEATURE_OSPKE);
- }
- }
- else
- b = c = d = 0;
- a = 0;
- break;
-
case 0x0000000a: /* Architectural Performance Monitor Features (Intel) */
if ( boot_cpu_data.x86_vendor != X86_VENDOR_INTEL ||
!vpmu_enabled(curr) )
@@ -1304,6 +1280,10 @@ void pv_cpuid(struct cpu_user_regs *regs)
unsupported:
a = b = c = d = 0;
break;
+
+ case 0x7:
+ ASSERT_UNREACHABLE();
+ /* Now handled in guest_cpuid(). */
}
regs->rax = a;
diff --git a/xen/include/asm-x86/cpuid.h b/xen/include/asm-x86/cpuid.h
index 9354e3a..5b1448a 100644
--- a/xen/include/asm-x86/cpuid.h
+++ b/xen/include/asm-x86/cpuid.h
@@ -81,12 +81,14 @@ struct cpuid_policy
* - {xcr0,xss}_{high,low}
*
* - Guest accurate:
+ * - All of the feat union
* - max_{,sub}leaf
* - All FEATURESET_* words
*
* Per-domain objects:
*
* - Guest accurate:
+ * - All of the feat union
* - max_{,sub}leaf
* - All FEATURESET_* words
*
--
generated by git-patchbot for /home/xen/git/xen.git#master
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