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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen master] x86/cpuid: Perform max_leaf calculations in guest_cpuid()
commit 1c0bc709d82afa84f7d67b9995f79c3c4b690735
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: Perform max_leaf calculations in guest_cpuid()
Clamp the toolstack-providied max_leaf values in recalculate_cpuid_policy(),
causing the per-domain policy to have guest-accurate data.
Have guest_cpuid() exit early if a requested leaf is out of range, rather
than
falling into the legacy path.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
xen/arch/x86/cpuid.c | 36 ++++++++++++++++++++++++++++++++++++
xen/arch/x86/hvm/hvm.c | 21 ---------------------
xen/arch/x86/traps.c | 23 -----------------------
xen/include/asm-x86/cpuid.h | 1 +
4 files changed, 37 insertions(+), 44 deletions(-)
diff --git a/xen/arch/x86/cpuid.c b/xen/arch/x86/cpuid.c
index c238776..c6552b7 100644
--- a/xen/arch/x86/cpuid.c
+++ b/xen/arch/x86/cpuid.c
@@ -283,6 +283,10 @@ void recalculate_cpuid_policy(struct domain *d)
uint32_t fs[FSCAPINTS], max_fs[FSCAPINTS];
unsigned int i;
+ p->basic.max_leaf = min(p->basic.max_leaf, max->basic.max_leaf);
+ p->feat.max_subleaf = min(p->feat.max_subleaf, max->feat.max_subleaf);
+ p->extd.max_leaf = min(p->extd.max_leaf, max->extd.max_leaf);
+
cpuid_policy_to_featureset(p, fs);
cpuid_policy_to_featureset(max, max_fs);
@@ -319,6 +323,9 @@ void recalculate_cpuid_policy(struct domain *d)
for ( i = 0; i < ARRAY_SIZE(fs); i++ )
fs[i] &= max_fs[i];
+ if ( p->basic.max_leaf < XSTATE_CPUID )
+ __clear_bit(X86_FEATURE_XSAVE, fs);
+
sanitise_featureset(fs);
/* Fold host's FDP_EXCP_ONLY and NO_FPU_SEL into guest's view. */
@@ -347,15 +354,36 @@ void guest_cpuid(const struct vcpu *v, uint32_t leaf,
uint32_t subleaf, struct cpuid_leaf *res)
{
const struct domain *d = v->domain;
+ const struct cpuid_policy *p = d->arch.cpuid;
*res = EMPTY_LEAF;
/*
* First pass:
+ * - Perform max_leaf/subleaf calculations. Out-of-range leaves return
+ * all zeros, following the AMD model.
* - Dispatch the virtualised leaves to their respective handlers.
*/
switch ( leaf )
{
+ case 0 ... CPUID_GUEST_NR_BASIC - 1:
+ if ( leaf > p->basic.max_leaf )
+ return;
+
+ switch ( leaf )
+ {
+ case 0x7:
+ if ( subleaf > p->feat.max_subleaf )
+ return;
+ break;
+
+ case XSTATE_CPUID:
+ if ( subleaf > ARRAY_SIZE(p->xstate.raw) )
+ return;
+ break;
+ }
+ break;
+
case 0x40000000 ... 0x400000ff:
if ( is_viridian_domain(d) )
return cpuid_viridian_leaves(v, leaf, subleaf, res);
@@ -368,6 +396,14 @@ void guest_cpuid(const struct vcpu *v, uint32_t leaf,
*/
case 0x40000100 ... 0x400001ff:
return cpuid_hypervisor_leaves(v, leaf, subleaf, res);
+
+ case 0x80000000 ... 0x80000000 + CPUID_GUEST_NR_EXTD - 1:
+ if ( leaf > p->extd.max_leaf )
+ return;
+ break;
+
+ default:
+ return;
}
/* {hvm,pv}_cpuid() have this expectation. */
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 82cb69b..e2af179 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3306,27 +3306,6 @@ void hvm_cpuid(unsigned int input, unsigned int *eax,
unsigned int *ebx,
if ( !edx )
edx = &dummy;
- if ( input & 0x7fffffff )
- {
- /*
- * Requests outside the supported leaf ranges return zero on AMD
- * and the highest basic leaf output on Intel. Uniformly follow
- * the AMD model as the more sane one.
- */
- unsigned int limit;
-
- domain_cpuid(d, (input >> 16) != 0x8000 ? 0 : 0x80000000, 0,
- &limit, &dummy, &dummy, &dummy);
- if ( input > limit )
- {
- *eax = 0;
- *ebx = 0;
- *ecx = 0;
- *edx = 0;
- return;
- }
- }
-
domain_cpuid(d, input, count, eax, ebx, ecx, edx);
switch ( input )
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index ef706af..6e08efe 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -1031,29 +1031,6 @@ void pv_cpuid(struct cpu_user_regs *regs)
subleaf = c = regs->_ecx;
d = regs->_edx;
- if ( leaf & 0x7fffffff )
- {
- /*
- * Requests outside the supported leaf ranges return zero on AMD
- * and the highest basic leaf output on Intel. Uniformly follow
- * the AMD model as the more sane one.
- */
- unsigned int limit = (leaf >> 16) != 0x8000 ? 0 : 0x80000000, dummy;
-
- if ( !is_control_domain(currd) && !is_hardware_domain(currd) )
- domain_cpuid(currd, limit, 0, &limit, &dummy, &dummy, &dummy);
- else
- limit = cpuid_eax(limit);
- if ( leaf > limit )
- {
- regs->rax = 0;
- regs->rbx = 0;
- regs->rcx = 0;
- regs->rdx = 0;
- return;
- }
- }
-
if ( !is_control_domain(currd) && !is_hardware_domain(currd) )
domain_cpuid(currd, leaf, subleaf, &a, &b, &c, &d);
else
diff --git a/xen/include/asm-x86/cpuid.h b/xen/include/asm-x86/cpuid.h
index 0f12c0c..9354e3a 100644
--- a/xen/include/asm-x86/cpuid.h
+++ b/xen/include/asm-x86/cpuid.h
@@ -87,6 +87,7 @@ struct cpuid_policy
* Per-domain objects:
*
* - Guest accurate:
+ * - max_{,sub}leaf
* - All FEATURESET_* words
*
* Everything else should be considered inaccurate, and not necesserily 0.
--
generated by git-patchbot for /home/xen/git/xen.git#master
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