* [V4] x86/xsaves: calculate the xstate_comp_offsets base on xstate_bv
@ 2016-03-16 12:12 Shuai Ruan
2016-03-22 10:53 ` Jan Beulich
0 siblings, 1 reply; 4+ messages in thread
From: Shuai Ruan @ 2016-03-16 12:12 UTC (permalink / raw)
To: xen-devel; +Cc: andrew.cooper3, keir, jbeulich
Previous patch using all available features calculate xstate_comp_offsets.
This is wrong.This patch fix this bug by calculating the xstate_comp_offset
based on xstate_bv of current guest.
Also, the xstate_comp_offset should take alignment into consideration.
Signed-off-by: Shuai Ruan <shuai.ruan@linux.intel.com>
Reported-by: Jan Beulich <jbeulich@suse.com>
---
V4: Address comments form jan:
1. use xstate_comp_offsets as on-stack array.
V3: Address comments from Jan:
1. fix xstate_comp_offsets used as static array problem.
2. change xstate_align from array to u64 and used as bitmap.
3. change calculating xstate_comp_offsets into three step.
1) whether component is set in xsavearea
2) whether component need align
3) add xstate_size[i-1]
V2: Address comments from Jan:
1. code style fix.
2. setup_xstate_comp take xcomp_bv as param.
xen/arch/x86/xstate.c | 53 ++++++++++++++++++++++++++++----------------
xen/include/asm-x86/xstate.h | 2 ++
2 files changed, 36 insertions(+), 19 deletions(-)
diff --git a/xen/arch/x86/xstate.c b/xen/arch/x86/xstate.c
index a5ed9e5..ef2c54d 100644
--- a/xen/arch/x86/xstate.c
+++ b/xen/arch/x86/xstate.c
@@ -26,8 +26,8 @@ u64 __read_mostly xfeature_mask;
static unsigned int *__read_mostly xstate_offsets;
unsigned int *__read_mostly xstate_sizes;
+static u64 __read_mostly xstate_align;
static unsigned int __read_mostly xstate_features;
-static unsigned int __read_mostly xstate_comp_offsets[sizeof(xfeature_mask)*8];
static uint32_t __read_mostly mxcsr_mask = 0x0000ffbf;
@@ -94,7 +94,7 @@ static bool_t xsave_area_compressed(const struct xsave_struct *xsave_area)
static int setup_xstate_features(bool_t bsp)
{
- unsigned int leaf, tmp, eax, ebx;
+ unsigned int leaf, eax, ebx, ecx, edx;
if ( bsp )
{
@@ -111,57 +111,70 @@ static int setup_xstate_features(bool_t bsp)
for ( leaf = 2; leaf < xstate_features; leaf++ )
{
if ( bsp )
+ {
cpuid_count(XSTATE_CPUID, leaf, &xstate_sizes[leaf],
- &xstate_offsets[leaf], &tmp, &tmp);
+ &xstate_offsets[leaf], &ecx, &edx);
+ if ( ecx & XSTATE_ALIGN64 )
+ __set_bit(leaf, &xstate_align);
+ }
else
{
cpuid_count(XSTATE_CPUID, leaf, &eax,
- &ebx, &tmp, &tmp);
+ &ebx, &ecx, &edx);
BUG_ON(eax != xstate_sizes[leaf]);
BUG_ON(ebx != xstate_offsets[leaf]);
+ BUG_ON((ecx & XSTATE_ALIGN64) != test_bit(leaf, &xstate_align));
}
}
return 0;
}
-static void __init setup_xstate_comp(void)
+static void setup_xstate_comp(uint16_t *xstate_comp_offsets,
+ const u64 xstate_bv)
{
unsigned int i;
+ uint16_t offset;
/*
* The FP xstates and SSE xstates are legacy states. They are always
* in the fixed offsets in the xsave area in either compacted form
* or standard form.
*/
- xstate_comp_offsets[0] = 0;
xstate_comp_offsets[1] = XSAVE_SSE_OFFSET;
xstate_comp_offsets[2] = FXSAVE_SIZE + XSAVE_HDR_SIZE;
- for ( i = 3; i < xstate_features; i++ )
+ offset = xstate_comp_offsets[2];
+ for ( i = 2; i < xstate_features; i++ )
{
- xstate_comp_offsets[i] = xstate_comp_offsets[i - 1] +
- (((1ul << i) & xfeature_mask)
- ? xstate_sizes[i - 1] : 0);
- ASSERT(xstate_comp_offsets[i] + xstate_sizes[i] <= xsave_cntxt_size);
+ if ( (1ul << i) & xstate_bv )
+ {
+ if ( test_bit(i, &xstate_align) )
+ offset = ROUNDUP(offset, 64);
+ xstate_comp_offsets[i] = offset;
+ offset += xstate_sizes[i];
+ ASSERT(offset <= xsave_cntxt_size);
+ }
}
}
static void *get_xsave_addr(struct xsave_struct *xsave,
- unsigned int xfeature_idx)
+ const uint16_t *xstate_comp_offsets,
+ unsigned int xfeature_idx)
{
if ( !((1ul << xfeature_idx) & xsave->xsave_hdr.xstate_bv) )
return NULL;
- return (void *)xsave + (xsave_area_compressed(xsave)
- ? xstate_comp_offsets
- : xstate_offsets)[xfeature_idx];
+ return (void *)xsave + ( xsave_area_compressed(xsave) ?
+ xstate_comp_offsets[xfeature_idx] :
+ xstate_offsets[xfeature_idx] );
}
void expand_xsave_states(struct vcpu *v, void *dest, unsigned int size)
{
struct xsave_struct *xsave = v->arch.xsave_area;
+ uint16_t xstate_comp_offsets[sizeof(xfeature_mask)*8];
u64 xstate_bv = xsave->xsave_hdr.xstate_bv;
u64 valid;
@@ -172,6 +185,8 @@ void expand_xsave_states(struct vcpu *v, void *dest, unsigned int size)
}
ASSERT(xsave_area_compressed(xsave));
+ setup_xstate_comp(xstate_comp_offsets, xstate_bv);
+
/*
* Copy legacy XSAVE area and XSAVE hdr area.
*/
@@ -188,7 +203,7 @@ void expand_xsave_states(struct vcpu *v, void *dest, unsigned int size)
{
u64 feature = valid & -valid;
unsigned int index = fls(feature) - 1;
- const void *src = get_xsave_addr(xsave, index);
+ const void *src = get_xsave_addr(xsave, xstate_comp_offsets, index);
if ( src )
{
@@ -203,6 +218,7 @@ void expand_xsave_states(struct vcpu *v, void *dest, unsigned int size)
void compress_xsave_states(struct vcpu *v, const void *src, unsigned int size)
{
struct xsave_struct *xsave = v->arch.xsave_area;
+ uint16_t xstate_comp_offsets[sizeof(xfeature_mask)*8];
u64 xstate_bv = ((const struct xsave_struct *)src)->xsave_hdr.xstate_bv;
u64 valid;
@@ -222,6 +238,7 @@ void compress_xsave_states(struct vcpu *v, const void *src, unsigned int size)
/* Set XSTATE_BV and XCOMP_BV. */
xsave->xsave_hdr.xstate_bv = xstate_bv;
xsave->xsave_hdr.xcomp_bv = v->arch.xcr0_accum | XSTATE_COMPACTION_ENABLED;
+ setup_xstate_comp(xstate_comp_offsets, xstate_bv);
/*
* Copy each region from the non-compacted offset to the
@@ -232,7 +249,7 @@ void compress_xsave_states(struct vcpu *v, const void *src, unsigned int size)
{
u64 feature = valid & -valid;
unsigned int index = fls(feature) - 1;
- void *dest = get_xsave_addr(xsave, index);
+ void *dest = get_xsave_addr(xsave, xstate_comp_offsets, index);
if ( dest )
{
@@ -575,8 +592,6 @@ void xstate_init(struct cpuinfo_x86 *c)
if ( setup_xstate_features(bsp) && bsp )
BUG();
- if ( bsp && (cpu_has_xsaves || cpu_has_xsavec) )
- setup_xstate_comp();
}
static bool_t valid_xcr0(u64 xcr0)
diff --git a/xen/include/asm-x86/xstate.h b/xen/include/asm-x86/xstate.h
index c28cea5..a488688 100644
--- a/xen/include/asm-x86/xstate.h
+++ b/xen/include/asm-x86/xstate.h
@@ -46,6 +46,8 @@
#define XSTATE_LAZY (XSTATE_ALL & ~XSTATE_NONLAZY)
#define XSTATE_COMPACTION_ENABLED (1ULL << 63)
+#define XSTATE_ALIGN64 (1U << 1)
+
extern u64 xfeature_mask;
extern unsigned int *xstate_sizes;
--
1.9.1
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [V4] x86/xsaves: calculate the xstate_comp_offsets base on xstate_bv
2016-03-16 12:12 [V4] x86/xsaves: calculate the xstate_comp_offsets base on xstate_bv Shuai Ruan
@ 2016-03-22 10:53 ` Jan Beulich
2016-03-23 1:28 ` Shuai Ruan
[not found] ` <20160323012803.GA4131@shuai.ruan@linux.intel.com>
0 siblings, 2 replies; 4+ messages in thread
From: Jan Beulich @ 2016-03-22 10:53 UTC (permalink / raw)
To: Shuai Ruan; +Cc: andrew.cooper3, keir, xen-devel
>>> On 16.03.16 at 13:12, <shuai.ruan@linux.intel.com> wrote:
Please have patch subjects have [PATCH at their beginning.
> @@ -111,57 +111,70 @@ static int setup_xstate_features(bool_t bsp)
> for ( leaf = 2; leaf < xstate_features; leaf++ )
> {
> if ( bsp )
> + {
> cpuid_count(XSTATE_CPUID, leaf, &xstate_sizes[leaf],
> - &xstate_offsets[leaf], &tmp, &tmp);
> + &xstate_offsets[leaf], &ecx, &edx);
> + if ( ecx & XSTATE_ALIGN64 )
> + __set_bit(leaf, &xstate_align);
> + }
> else
> {
> cpuid_count(XSTATE_CPUID, leaf, &eax,
> - &ebx, &tmp, &tmp);
> + &ebx, &ecx, &edx);
> BUG_ON(eax != xstate_sizes[leaf]);
> BUG_ON(ebx != xstate_offsets[leaf]);
> + BUG_ON((ecx & XSTATE_ALIGN64) != test_bit(leaf, &xstate_align));
Neither side of the != seems correct: The left side would produce
0 or 2 (instead of 0 or 1), while the right side may produce any
non-zero value for truth.
> -static void __init setup_xstate_comp(void)
> +static void setup_xstate_comp(uint16_t *xstate_comp_offsets,
> + const u64 xstate_bv)
> {
> unsigned int i;
> + uint16_t offset;
>
> /*
> * The FP xstates and SSE xstates are legacy states. They are always
> * in the fixed offsets in the xsave area in either compacted form
> * or standard form.
> */
> - xstate_comp_offsets[0] = 0;
With the array now being uninitialized again you should no
longer delete this.
> xstate_comp_offsets[1] = XSAVE_SSE_OFFSET;
>
> xstate_comp_offsets[2] = FXSAVE_SIZE + XSAVE_HDR_SIZE;
>
> - for ( i = 3; i < xstate_features; i++ )
> + offset = xstate_comp_offsets[2];
> + for ( i = 2; i < xstate_features; i++ )
> {
> - xstate_comp_offsets[i] = xstate_comp_offsets[i - 1] +
> - (((1ul << i) & xfeature_mask)
> - ? xstate_sizes[i - 1] : 0);
> - ASSERT(xstate_comp_offsets[i] + xstate_sizes[i] <= xsave_cntxt_size);
> + if ( (1ul << i) & xstate_bv )
> + {
> + if ( test_bit(i, &xstate_align) )
> + offset = ROUNDUP(offset, 64);
> + xstate_comp_offsets[i] = offset;
> + offset += xstate_sizes[i];
> + ASSERT(offset <= xsave_cntxt_size);
This would seem to better go after the loop now that it's
independent of the loop variable. Also at least for this purpose
I think it would be better is "offset" was "unsigned int".
> static void *get_xsave_addr(struct xsave_struct *xsave,
> - unsigned int xfeature_idx)
> + const uint16_t *xstate_comp_offsets,
> + unsigned int xfeature_idx)
> {
> if ( !((1ul << xfeature_idx) & xsave->xsave_hdr.xstate_bv) )
> return NULL;
>
> - return (void *)xsave + (xsave_area_compressed(xsave)
> - ? xstate_comp_offsets
> - : xstate_offsets)[xfeature_idx];
> + return (void *)xsave + ( xsave_area_compressed(xsave) ?
> + xstate_comp_offsets[xfeature_idx] :
> + xstate_offsets[xfeature_idx] );
Stray blanks inside the parentheses.
> void expand_xsave_states(struct vcpu *v, void *dest, unsigned int size)
> {
> struct xsave_struct *xsave = v->arch.xsave_area;
> + uint16_t xstate_comp_offsets[sizeof(xfeature_mask)*8];
There's no point in prefixing a local variable in this file with xstate_.
And the same goes for the function parameters earlier on.
> @@ -172,6 +185,8 @@ void expand_xsave_states(struct vcpu *v, void *dest, unsigned int size)
> }
>
> ASSERT(xsave_area_compressed(xsave));
> + setup_xstate_comp(xstate_comp_offsets, xstate_bv);
Don't you need to use xcomp_bv here? That's what "Extended
Region of an XSAVE Area" in SDM Vol 1 suggests to me.
> @@ -222,6 +238,7 @@ void compress_xsave_states(struct vcpu *v, const void *src, unsigned int size)
> /* Set XSTATE_BV and XCOMP_BV. */
> xsave->xsave_hdr.xstate_bv = xstate_bv;
> xsave->xsave_hdr.xcomp_bv = v->arch.xcr0_accum | XSTATE_COMPACTION_ENABLED;
> + setup_xstate_comp(xstate_comp_offsets, xstate_bv);
Same here then I think.
Jan
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [V4] x86/xsaves: calculate the xstate_comp_offsets base on xstate_bv
2016-03-22 10:53 ` Jan Beulich
@ 2016-03-23 1:28 ` Shuai Ruan
[not found] ` <20160323012803.GA4131@shuai.ruan@linux.intel.com>
1 sibling, 0 replies; 4+ messages in thread
From: Shuai Ruan @ 2016-03-23 1:28 UTC (permalink / raw)
To: Jan Beulich; +Cc: andrew.cooper3, keir, xen-devel
On Tue, Mar 22, 2016 at 04:53:02AM -0600, Jan Beulich wrote:
> >>> On 16.03.16 at 13:12, <shuai.ruan@linux.intel.com> wrote:
>
> Don't you need to use xcomp_bv here? That's what "Extended
> Region of an XSAVE Area" in SDM Vol 1 suggests to me.
>
"OPERATION OF XRSTORS" and "OPERATION OF XSAVES" in SDM Vol1.
For xsaves:
"Execution of XSAVES performs the init optimization to reduce the amount
of data written to memory."
For xrstors:
"XRSTORS updates state component i based on the value of bit i in the
XSTATE_BV field of the XSAVE header".
> > /* Set XSTATE_BV and XCOMP_BV. */
> > xsave->xsave_hdr.xstate_bv = xstate_bv;
> > xsave->xsave_hdr.xcomp_bv = v->arch.xcr0_accum | XSTATE_COMPACTION_ENABLED;
> > + setup_xstate_comp(xstate_comp_offsets, xstate_bv);
>
> Same here then I think.
>
> Jan
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 4+ messages in thread
[parent not found: <20160323012803.GA4131@shuai.ruan@linux.intel.com>]
* Re: [V4] x86/xsaves: calculate the xstate_comp_offsets base on xstate_bv
[not found] ` <20160323012803.GA4131@shuai.ruan@linux.intel.com>
@ 2016-03-23 3:28 ` Shuai Ruan
0 siblings, 0 replies; 4+ messages in thread
From: Shuai Ruan @ 2016-03-23 3:28 UTC (permalink / raw)
To: Jan Beulich; +Cc: andrew.cooper3, keir, xen-devel
On Wed, Mar 23, 2016 at 09:28:03AM +0800, Shuai Ruan wrote:
> On Tue, Mar 22, 2016 at 04:53:02AM -0600, Jan Beulich wrote:
> > >>> On 16.03.16 at 13:12, <shuai.ruan@linux.intel.com> wrote:
> >
> > Don't you need to use xcomp_bv here? That's what "Extended
> > Region of an XSAVE Area" in SDM Vol 1 suggests to me.
> >
> "OPERATION OF XRSTORS" and "OPERATION OF XSAVES" in SDM Vol1.
>
> For xsaves:
> "Execution of XSAVES performs the init optimization to reduce the amount
> of data written to memory."
>
> For xrstors:
> "XRSTORS updates state component i based on the value of bit i in the
> XSTATE_BV field of the XSAVE header".
>
Ignore this. You are right.
I misunderstand some XSAVES/XRSTORS behaviors in SDM . In the previous versions,
I use xcom_bv to caculate comp_offset (but changing to xstate_bv in this
version:( ).
Thanks.
> > > /* Set XSTATE_BV and XCOMP_BV. */
> > > xsave->xsave_hdr.xstate_bv = xstate_bv;
> > > xsave->xsave_hdr.xcomp_bv = v->arch.xcr0_accum | XSTATE_COMPACTION_ENABLED;
> > > + setup_xstate_comp(xstate_comp_offsets, xstate_bv);
> >
> > Same here then I think.
> >
> > Jan
> >
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@lists.xen.org
> > http://lists.xen.org/xen-devel
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-03-23 3:28 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-03-16 12:12 [V4] x86/xsaves: calculate the xstate_comp_offsets base on xstate_bv Shuai Ruan
2016-03-22 10:53 ` Jan Beulich
2016-03-23 1:28 ` Shuai Ruan
[not found] ` <20160323012803.GA4131@shuai.ruan@linux.intel.com>
2016-03-23 3:28 ` Shuai Ruan
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).