From: Paolo Bonzini <pbonzini@redhat.com>
To: Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, "Chang S. Bae" <chang.seok.bae@intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Arjan van de Ven <arjan@linux.intel.com>,
kvm@vger.kernel.org
Subject: Re: [patch 15/31] x86/fpu: Rework copy_xstate_to_uabi_buf()
Date: Tue, 12 Oct 2021 19:30:58 +0200 [thread overview]
Message-ID: <bbf53506-43df-78cc-c954-ed4e8384b1d2@redhat.com> (raw)
In-Reply-To: <20211011223611.189084655@linutronix.de>
On 12/10/21 02:00, Thomas Gleixner wrote:
> Prepare for replacing the KVM copy xstate to user function by extending
> copy_xstate_to_uabi_buf() with a pkru argument which allows the caller to
> hand in the pkru value, which is required for KVM because the guest PKRU is
> not accessible via current. Fixup all callsites accordingly.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
> arch/x86/kernel/fpu/xstate.c | 34 ++++++++++++++++++++++++++--------
> arch/x86/kernel/fpu/xstate.h | 3 +++
> 2 files changed, 29 insertions(+), 8 deletions(-)
>
> --- a/arch/x86/kernel/fpu/xstate.c
> +++ b/arch/x86/kernel/fpu/xstate.c
> @@ -940,9 +940,10 @@ static void copy_feature(bool from_xstat
> }
>
> /**
> - * copy_xstate_to_uabi_buf - Copy kernel saved xstate to a UABI buffer
> + * __copy_xstate_to_uabi_buf - Copy kernel saved xstate to a UABI buffer
> * @to: membuf descriptor
> - * @tsk: The task from which to copy the saved xstate
> + * @xsave: The xsave from which to copy
> + * @pkru_val: The PKRU value to store in the PKRU component
> * @copy_mode: The requested copy mode
> *
> * Converts from kernel XSAVE or XSAVES compacted format to UABI conforming
> @@ -951,11 +952,10 @@ static void copy_feature(bool from_xstat
> *
> * It supports partial copy but @to.pos always starts from zero.
> */
> -void copy_xstate_to_uabi_buf(struct membuf to, struct task_struct *tsk,
> - enum xstate_copy_mode copy_mode)
> +void __copy_xstate_to_uabi_buf(struct membuf to, struct xregs_state *xsave,
> + u32 pkru_val, enum xstate_copy_mode copy_mode)
> {
> const unsigned int off_mxcsr = offsetof(struct fxregs_state, mxcsr);
> - struct xregs_state *xsave = &tsk->thread.fpu.state.xsave;
> struct xregs_state *xinit = &init_fpstate.xsave;
> struct xstate_header header;
> unsigned int zerofrom;
> @@ -1033,10 +1033,9 @@ void copy_xstate_to_uabi_buf(struct memb
> struct pkru_state pkru = {0};
> /*
> * PKRU is not necessarily up to date in the
> - * thread's XSAVE buffer. Fill this part from the
> - * per-thread storage.
> + * XSAVE buffer. Use the provided value.
> */
> - pkru.pkru = tsk->thread.pkru;
> + pkru.pkru = pkru_val;
> membuf_write(&to, &pkru, sizeof(pkru));
> } else {
> copy_feature(header.xfeatures & BIT_ULL(i), &to,
> @@ -1056,6 +1055,25 @@ void copy_xstate_to_uabi_buf(struct memb
> membuf_zero(&to, to.left);
> }
>
> +/**
> + * copy_xstate_to_uabi_buf - Copy kernel saved xstate to a UABI buffer
> + * @to: membuf descriptor
> + * @tsk: The task from which to copy the saved xstate
> + * @copy_mode: The requested copy mode
> + *
> + * Converts from kernel XSAVE or XSAVES compacted format to UABI conforming
> + * format, i.e. from the kernel internal hardware dependent storage format
> + * to the requested @mode. UABI XSTATE is always uncompacted!
> + *
> + * It supports partial copy but @to.pos always starts from zero.
> + */
> +void copy_xstate_to_uabi_buf(struct membuf to, struct task_struct *tsk,
> + enum xstate_copy_mode copy_mode)
> +{
> + __copy_xstate_to_uabi_buf(to, &tsk->thread.fpu.state.xsave,
> + tsk->thread.pkru, copy_mode);
> +}
> +
> static int copy_from_buffer(void *dst, unsigned int offset, unsigned int size,
> const void *kbuf, const void __user *ubuf)
> {
> --- a/arch/x86/kernel/fpu/xstate.h
> +++ b/arch/x86/kernel/fpu/xstate.h
> @@ -15,4 +15,7 @@ static inline void xstate_init_xcomp_bv(
> xsave->header.xcomp_bv = mask | XCOMP_BV_COMPACTED_FORMAT;
> }
>
> +extern void __copy_xstate_to_uabi_buf(struct membuf to, struct xregs_state *xsave,
> + u32 pkru_val, enum xstate_copy_mode copy_mode);
> +
> #endif
>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
next prev parent reply other threads:[~2021-10-12 17:31 UTC|newest]
Thread overview: 96+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-11 23:59 [patch 00/31] x86/fpu: Preparatory cleanups for AMX support (part 1) Thomas Gleixner
2021-10-11 23:59 ` [patch 01/31] x86/fpu: Remove pointless argument from switch_fpu_finish() Thomas Gleixner
2021-10-12 0:00 ` [patch 02/31] x86/fpu: Update stale comments Thomas Gleixner
2021-10-12 0:00 ` [patch 03/31] x86/pkru: Remove useless include Thomas Gleixner
2021-10-12 0:00 ` [patch 04/31] x86/fpu: Restrict xsaves()/xrstors() to independent states Thomas Gleixner
2021-10-12 14:24 ` Borislav Petkov
2021-10-12 0:00 ` [patch 05/31] x86/fpu: Cleanup the on_boot_cpu clutter Thomas Gleixner
2021-10-12 0:00 ` [patch 06/31] x86/fpu: Remove pointless memset in fpu_clone() Thomas Gleixner
2021-10-12 0:00 ` [patch 07/31] x86/process: Clone FPU in copy_thread() Thomas Gleixner
2021-10-12 0:00 ` [patch 08/31] x86/fpu: Do not inherit FPU context for kernel and IO worker threads Thomas Gleixner
2021-10-12 0:00 ` [patch 09/31] x86/fpu: Do not inherit FPU context for CLONE_THREAD Thomas Gleixner
2021-10-12 16:10 ` Borislav Petkov
2021-10-12 18:52 ` Thomas Gleixner
2021-10-12 19:01 ` Thomas Gleixner
2021-10-12 0:00 ` [patch 10/31] x86/fpu: Cleanup xstate xcomp_bv initialization Thomas Gleixner
2021-10-12 0:00 ` [patch 11/31] x86/fpu/xstate: Provide and use for_each_xfeature() Thomas Gleixner
2021-10-12 16:45 ` Borislav Petkov
2021-10-12 0:00 ` [patch 12/31] x86/fpu/xstate: Mark all init only functions __init Thomas Gleixner
2021-10-12 0:00 ` [patch 13/31] x86/fpu: Move KVMs FPU swapping to FPU core Thomas Gleixner
2021-10-12 16:53 ` Borislav Petkov
2021-10-12 18:25 ` Thomas Gleixner
2021-10-12 18:26 ` Thomas Gleixner
2021-10-12 17:22 ` Paolo Bonzini
2021-10-13 6:15 ` Liu, Jing2
2021-10-13 6:26 ` Paolo Bonzini
2021-10-13 7:46 ` Liu, Jing2
2021-10-13 8:42 ` Paolo Bonzini
2021-10-13 10:14 ` Andy Lutomirski
2021-10-13 12:26 ` Paolo Bonzini
2021-10-13 14:14 ` Thomas Gleixner
2021-10-13 14:24 ` Thomas Gleixner
2021-10-13 14:59 ` Andy Lutomirski
2021-10-13 15:05 ` Paolo Bonzini
2021-10-13 10:25 ` Liu, Jing2
2021-10-13 12:37 ` Paolo Bonzini
2021-10-13 14:06 ` Thomas Gleixner
2021-10-14 6:50 ` Paolo Bonzini
2021-10-14 8:02 ` Liu, Jing2
2021-10-14 9:01 ` Paolo Bonzini
2021-10-14 11:21 ` Liu, Jing2
2021-10-14 11:33 ` Paolo Bonzini
2021-10-14 11:30 ` Liu, Jing2
2021-10-14 11:39 ` Paolo Bonzini
2021-11-22 8:50 ` Liu, Jing2
2021-10-14 14:09 ` Thomas Gleixner
2021-10-14 14:37 ` Thomas Gleixner
2021-10-14 15:01 ` Paolo Bonzini
2021-10-14 19:14 ` Thomas Gleixner
2021-10-15 9:20 ` Liu, Jing2
2021-10-15 9:36 ` Thomas Gleixner
2021-10-15 14:24 ` Liu, Jing2
2021-10-15 15:53 ` Paolo Bonzini
2021-10-16 14:45 ` Thomas Gleixner
2021-10-15 9:00 ` Liu, Jing2
2021-10-15 10:50 ` Thomas Gleixner
2021-10-15 11:17 ` Paolo Bonzini
2021-10-15 13:01 ` Liu, Jing2
2021-10-14 12:23 ` Thomas Gleixner
2021-10-14 12:26 ` Paolo Bonzini
2021-10-14 14:23 ` Thomas Gleixner
2021-10-13 15:12 ` Thomas Gleixner
2021-10-14 8:21 ` Liu, Jing2
2021-10-14 13:08 ` Thomas Gleixner
2021-10-12 0:00 ` [patch 14/31] x86/fpu: Replace KVMs homebrewn FPU copy from user Thomas Gleixner
2021-10-12 17:00 ` Borislav Petkov
2021-10-13 14:57 ` Sean Christopherson
2021-10-13 15:12 ` Paolo Bonzini
2021-10-13 15:16 ` Thomas Gleixner
2021-10-12 17:30 ` Paolo Bonzini
2021-10-12 0:00 ` [patch 15/31] x86/fpu: Rework copy_xstate_to_uabi_buf() Thomas Gleixner
2021-10-12 17:30 ` Paolo Bonzini [this message]
2021-10-12 0:00 ` [patch 16/31] x86/fpu: Replace KVMs homebrewn FPU copy to user Thomas Gleixner
2021-10-12 17:10 ` Borislav Petkov
2021-10-12 17:36 ` Paolo Bonzini
2021-10-12 17:47 ` Thomas Gleixner
2021-10-12 18:40 ` [patch V2 16/31] x86/fpu: Replace KVMs home brewed " Thomas Gleixner
2021-10-13 5:34 ` [patch 16/31] x86/fpu: Replace KVMs homebrewn " Paolo Bonzini
2021-10-12 0:00 ` [patch 17/31] x86/fpu: Mark fpu__init_prepare_fx_sw_frame() as __init Thomas Gleixner
2021-10-12 0:00 ` [patch 18/31] x86/fpu: Move context switch and exit to user inlines into sched.h Thomas Gleixner
2021-10-12 0:00 ` [patch 19/31] x86/fpu: Clean up cpu feature tests Thomas Gleixner
2021-10-12 0:00 ` [patch 20/31] x86/fpu: Make os_xrstor_booting() private Thomas Gleixner
2021-10-12 0:00 ` [patch 21/31] x86/fpu: Move os_xsave() and os_xrstor() to core Thomas Gleixner
2021-10-12 0:00 ` [patch 22/31] x86/fpu: Move legacy ASM wrappers " Thomas Gleixner
2021-10-12 0:00 ` [patch 23/31] x86/fpu: Make WARN_ON_FPU() private Thomas Gleixner
2021-10-12 0:00 ` [patch 24/31] x86/fpu: Move fpregs_restore_userregs() to core Thomas Gleixner
2021-10-12 17:32 ` Borislav Petkov
2021-10-12 0:00 ` [patch 25/31] x86/fpu: Move mxcsr related code " Thomas Gleixner
2021-10-12 0:00 ` [patch 26/31] x86/fpu: Move fpstate functions to api.h Thomas Gleixner
2021-10-12 17:46 ` Borislav Petkov
2021-10-12 0:00 ` [patch 27/31] x86/fpu: Remove internal.h dependency from fpu/signal.h Thomas Gleixner
2021-10-12 0:00 ` [patch 28/31] x86/sev: Include fpu/xcr.h Thomas Gleixner
2021-10-12 7:24 ` Xiaoyao Li
2021-10-12 0:00 ` [patch 29/31] x86/fpu: Mop up the internal.h leftovers Thomas Gleixner
2021-10-12 0:00 ` [patch 30/31] x86/fpu: Replace the includes of fpu/internal.h Thomas Gleixner
2021-10-12 0:00 ` [patch 31/31] x86/fpu: Provide a proper function for ex_handler_fprestore() Thomas Gleixner
2021-10-12 21:15 ` [patch 00/31] x86/fpu: Preparatory cleanups for AMX support (part 1) Thomas Gleixner
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