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compel: support XSAVE on newer Intel CPUs

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Newer Intel CPUs (Sapphire Rapids) have a much larger xsave area than
before. Looking at older CPUs I see 2440 bytes.

    # cpuid -1 -l 0xd -s 0
    ...
        bytes required by XSAVE/XRSTOR area     = 0x00000988 (2440)

On newer CPUs (Sapphire Rapids) it grows to 11008 bytes.

    # cpuid -1 -l 0xd -s 0
    ...
        bytes required by XSAVE/XRSTOR area     = 0x00002b00 (11008)

This increase the xsave area from one page to four pages.

Without this patch the fpu03 test fails, with this patch it works again.

Signed-off-by: Adrian Reber <areber@redhat.com>
This commit is contained in:
Adrian Reber 2023-04-24 09:28:19 +02:00 • committed by Andrei Vagin
parent 13eb87606e
commit 970c4abe7b
1 changed files with 26 additions and 2 deletions
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28
compel/arch/x86/src/lib/include/uapi/asm/fpu.h
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@ -21,7 +21,28 @@
#define XSTATE_YMM 0x4
#define FXSAVE_SIZE 512
#define XSAVE_SIZE 4096
/*
* This used to be 4096 (one page). There is a comment below concerning
* this size:
* "One page should be enough for the whole xsave state ;-)"
* Which is kind of funny as it is no longer enough ;-)
*
* Older CPUs:
* # cpuid -1 -l 0xd -s 0
* ...
* bytes required by XSAVE/XRSTOR area = 0x00000988 (2440)
*
* Newer CPUs (Sapphire Rapids):
* # cpuid -1 -l 0xd -s 0
* ...
* bytes required by XSAVE/XRSTOR area = 0x00002b00 (11008)
*
* So one page is no longer enough... But:
*
* Four pages should be enough for the whole xsave state ;-)
*/
#define XSAVE_SIZE 4*4096
#define XSAVE_HDR_SIZE 64
#define XSAVE_HDR_OFFSET FXSAVE_SIZE
@ -235,8 +256,11 @@ struct pkru_state {
*
*
* One page should be enough for the whole xsave state ;-)
*
* Of course it was not ;-) Now using four pages...
*
*/
#define EXTENDED_STATE_AREA_SIZE (4096 - sizeof(struct i387_fxsave_struct) - sizeof(struct xsave_hdr_struct))
#define EXTENDED_STATE_AREA_SIZE (XSAVE_SIZE - sizeof(struct i387_fxsave_struct) - sizeof(struct xsave_hdr_struct))
/*
* cpu requires it to be 64 byte aligned