From: Shuai Ruan <shuai.ruan@linux.intel.com>
To: xen-devel@lists.xen.org
Cc: andrew.cooper3@citrix.com, keir@xen.org, jbeulich@suse.com
Subject: [PATCH V7 3/3] x86/xsaves: ebx may return wrong value using CPUID eax=0xdh, ecx =1
Date: Thu, 31 Mar 2016 16:57:37 +0800 [thread overview]
Message-ID: <1459414657-7558-4-git-send-email-shuai.ruan@linux.intel.com> (raw)
In-Reply-To: <1459414657-7558-1-git-send-email-shuai.ruan@linux.intel.com>
From: Shuai Ruan <shuai.ruan@intel.com>
Refer to SDM 13.4.3 Extended Region of an XSAVE Area. The value return
by ecx[1] with cpuid function 0xdh and sub-fucntion i (i>1) indicates
the alignment of the state component i when the compacted format of the
extended region of an xsave area is used.
So when hvm/pv guest using CPUID eax=0xdh,ecx=1 to get the size of area
used for compacted format, we need to take alignment into consideration.
tools side is fixed by
"tools/libxc: Calculate xstate cpuid leaf from guest information"
by Andrew Cooper
Signed-off-by: Shuai Ruan <shuai.ruan@intel.com>
---
v2: Address comments by Jan:
1. take alignment into consideration in pv_cpuid.
2. fix coding style issues
xen/arch/x86/hvm/hvm.c | 6 +++++-
xen/arch/x86/traps.c | 12 ++++++++++++
xen/arch/x86/xstate.c | 2 +-
xen/include/asm-x86/xstate.h | 1 +
4 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 5aef3cb..c6cd4fb 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4743,14 +4743,18 @@ void hvm_cpuid(unsigned int input, unsigned int *eax, unsigned int *ebx,
}
if ( count == 1 )
{
- if ( cpu_has_xsaves && cpu_has_vmx_xsaves )
+ if ( (cpu_has_xsaves && cpu_has_vmx_xsaves) || cpu_has_xsavec )
{
*ebx = XSTATE_AREA_MIN_SIZE;
if ( v->arch.xcr0 | v->arch.hvm_vcpu.msr_xss )
for ( sub_leaf = 2; sub_leaf < 63; sub_leaf++ )
if ( (v->arch.xcr0 | v->arch.hvm_vcpu.msr_xss) &
(1ULL << sub_leaf) )
+ {
+ if ( test_bit(sub_leaf, &xstate_align) )
+ *ebx = ROUNDUP(*ebx, 64);
*ebx += xstate_sizes[sub_leaf];
+ }
}
else
*ebx = *ecx = *edx = 0;
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 6fbb1cf..8694da6 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -1020,6 +1020,18 @@ void pv_cpuid(struct cpu_user_regs *regs)
a &= (boot_cpu_data.x86_capability[cpufeat_word(X86_FEATURE_XSAVEOPT)] &
~cpufeat_mask(X86_FEATURE_XSAVES));
b = c = d = 0;
+ if ( cpu_has_xsavec )
+ {
+ b = XSTATE_AREA_MIN_SIZE;
+ if ( curr->arch.xcr0 )
+ for( subleaf = 2; subleaf < 63; subleaf++ )
+ if ( (1ULL << subleaf) & curr->arch.xcr0 )
+ {
+ if ( test_bit(subleaf, &xstate_align) )
+ b = ROUNDUP(b, 64);
+ b += xstate_sizes[subleaf];
+ }
+ }
break;
}
break;
diff --git a/xen/arch/x86/xstate.c b/xen/arch/x86/xstate.c
index f4ea54d..850b778 100644
--- a/xen/arch/x86/xstate.c
+++ b/xen/arch/x86/xstate.c
@@ -26,7 +26,7 @@ u64 __read_mostly xfeature_mask;
static unsigned int *__read_mostly xstate_offsets;
unsigned int *__read_mostly xstate_sizes;
-static u64 __read_mostly xstate_align;
+u64 __read_mostly xstate_align;
static unsigned int __read_mostly xstate_features;
static uint32_t __read_mostly mxcsr_mask = 0x0000ffbf;
diff --git a/xen/include/asm-x86/xstate.h b/xen/include/asm-x86/xstate.h
index 91d1c39..535443a 100644
--- a/xen/include/asm-x86/xstate.h
+++ b/xen/include/asm-x86/xstate.h
@@ -50,6 +50,7 @@
#define XSTATE_ALIGN64 (1U << 1)
extern u64 xfeature_mask;
+extern u64 xstate_align;
extern unsigned int *xstate_sizes;
/* extended state save area */
--
1.9.1
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next prev parent reply other threads:[~2016-03-31 8:57 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-31 8:57 [PATCH V7 0/3] xsaves bug fix Shuai Ruan
2016-03-31 8:57 ` [PATCH V7 1/3] x86/xsaves: fix overwriting between non-lazy/lazy xsaves Shuai Ruan
2016-04-04 15:51 ` Jan Beulich
2016-04-05 5:30 ` Shuai Ruan
[not found] ` <20160405053023.GA16876@shuai.ruan@linux.intel.com>
2016-04-05 7:17 ` Jan Beulich
2016-04-05 7:29 ` Shuai Ruan
2016-04-25 6:51 ` Jan Beulich
2016-04-29 1:36 ` Shuai Ruan
[not found] ` <20160429013616.GB4359@shuai.ruan@linux.intel.com>
2016-04-29 7:05 ` Jan Beulich
2016-03-31 8:57 ` [PATCH V7 2/3] x86/xsaves: fix two remained issues Shuai Ruan
2016-04-04 16:03 ` Jan Beulich
2016-03-31 8:57 ` Shuai Ruan [this message]
2016-04-05 8:31 ` [PATCH V7 3/3] x86/xsaves: ebx may return wrong value using CPUID eax=0xdh, ecx =1 Jan Beulich
2016-04-06 7:01 ` Shuai Ruan
[not found] ` <20160406070034.GA26357@shuai.ruan@linux.intel.com>
2016-04-07 0:29 ` Jan Beulich
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