From: Thomas Gleixner <tglx@linutronix.de>
To: Yang Zhong <yang.zhong@intel.com>,
x86@kernel.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, mingo@redhat.com, bp@alien8.de,
dave.hansen@linux.intel.com, pbonzini@redhat.com
Cc: seanjc@google.com, jun.nakajima@intel.com, kevin.tian@intel.com,
jing2.liu@linux.intel.com, jing2.liu@intel.com,
yang.zhong@intel.com
Subject: Re: [PATCH 10/19] kvm: x86: Emulate WRMSR of guest IA32_XFD
Date: Sat, 11 Dec 2021 00:09:47 +0100 [thread overview]
Message-ID: <87zgp8vyys.ffs@tglx> (raw)
In-Reply-To: <20211208000359.2853257-11-yang.zhong@intel.com>
On Tue, Dec 07 2021 at 19:03, Yang Zhong wrote:
> +
> + /*
> + * Update IA32_XFD to the guest value so #NM can be
> + * raised properly in the guest. Instead of directly
> + * writing the MSR, call a helper to avoid breaking
> + * per-cpu cached value in fpu core.
> + */
> + fpregs_lock();
> + current->thread.fpu.fpstate->xfd = data;
> + xfd_update_state(current->thread.fpu.fpstate);
> + fpregs_unlock();
> + break;
Now looking at the actual callsite the previous patch really should be
something like the below. Why?
It preserves the inline which allows the compiler to generate better
code in the other hotpathes and it keeps the FPU internals to the core
code. Hmm?
Thanks,
tglx
--- a/arch/x86/include/asm/fpu/api.h
+++ b/arch/x86/include/asm/fpu/api.h
@@ -125,8 +125,10 @@ DECLARE_PER_CPU(struct fpu *, fpu_fpregs
/* Process cleanup */
#ifdef CONFIG_X86_64
extern void fpstate_free(struct fpu *fpu);
+extern void fpu_update_xfd_state(u64 xfd);
#else
static inline void fpstate_free(struct fpu *fpu) { }
+static inline void fpu_update_xfd_state(u64 xfd) { }
#endif
/* fpstate-related functions which are exported to KVM */
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -322,6 +322,19 @@ int fpu_swap_kvm_fpstate(struct fpu_gues
}
EXPORT_SYMBOL_GPL(fpu_swap_kvm_fpstate);
+#ifdef CONFIG_X86_64
+void fpu_update_xfd_state(u64 xfd)
+{
+ struct fpstate *fps = current->thread.fpu.fpstate;
+
+ fpregs_lock();
+ fps->xfd = xfd;
+ xfd_update_state(fps);
+ fpregs_unlock();
+}
+EXPORT_SYMBOL_GPL(fpu_update_xfd_state);
+#endif
+
void fpu_copy_guest_fpstate_to_uabi(struct fpu_guest *gfpu, void *buf,
unsigned int size, u32 pkru)
{
next prev parent reply other threads:[~2021-12-10 23:09 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-08 0:03 [PATCH 00/19] AMX Support in KVM Yang Zhong
2021-12-08 0:03 ` [PATCH 01/19] x86/fpu: Extend prctl() with guest permissions Yang Zhong
2021-12-14 0:16 ` Thomas Gleixner
2021-12-08 0:03 ` [PATCH 02/19] x86/fpu: Prepare KVM for dynamically enabled states Yang Zhong
2021-12-13 9:12 ` Paolo Bonzini
2021-12-13 12:00 ` Thomas Gleixner
2021-12-13 12:45 ` Paolo Bonzini
2021-12-13 19:50 ` Thomas Gleixner
2021-12-08 0:03 ` [PATCH 03/19] kvm: x86: Fix xstate_required_size() to follow XSTATE alignment rule Yang Zhong
2021-12-08 0:03 ` [PATCH 04/19] kvm: x86: Check guest xstate permissions when KVM_SET_CPUID2 Yang Zhong
2021-12-08 0:03 ` [PATCH 05/19] x86/fpu: Move xfd initialization out of __fpstate_reset() to the callers Yang Zhong
2021-12-10 22:33 ` Thomas Gleixner
2021-12-08 0:03 ` [PATCH 06/19] x86/fpu: Add reallocation mechanims for KVM Yang Zhong
2021-12-08 0:03 ` [PATCH 07/19] kvm: x86: Propagate fpstate reallocation error to userspace Yang Zhong
2021-12-10 15:44 ` Paolo Bonzini
2021-12-08 0:03 ` [PATCH 08/19] x86/fpu: Move xfd_update_state() to xstate.c and export symbol Yang Zhong
2021-12-10 22:44 ` Thomas Gleixner
2021-12-08 0:03 ` [PATCH 09/19] kvm: x86: Prepare reallocation check Yang Zhong
2021-12-13 9:16 ` Paolo Bonzini
2021-12-14 7:06 ` Tian, Kevin
2021-12-14 10:16 ` Paolo Bonzini
2021-12-14 14:41 ` Liu, Jing2
2021-12-15 7:09 ` Tian, Kevin
2021-12-08 0:03 ` [PATCH 10/19] kvm: x86: Emulate WRMSR of guest IA32_XFD Yang Zhong
2021-12-10 16:02 ` Paolo Bonzini
2021-12-13 7:51 ` Liu, Jing2
2021-12-13 9:01 ` Paolo Bonzini
2021-12-14 10:26 ` Yang Zhong
2021-12-14 11:24 ` Paolo Bonzini
2021-12-10 23:09 ` Thomas Gleixner [this message]
2021-12-13 15:06 ` Paolo Bonzini
2021-12-13 19:45 ` Thomas Gleixner
2021-12-13 21:23 ` Thomas Gleixner
2021-12-14 7:16 ` Tian, Kevin
2021-12-08 0:03 ` [PATCH 11/19] kvm: x86: Check fpstate reallocation in XSETBV emulation Yang Zhong
2021-12-08 0:03 ` [PATCH 12/19] x86/fpu: Prepare KVM for bringing XFD state back in-sync Yang Zhong
2021-12-10 23:11 ` Thomas Gleixner
2021-12-08 0:03 ` [PATCH 13/19] kvm: x86: Disable WRMSR interception for IA32_XFD on demand Yang Zhong
2021-12-08 7:23 ` Liu, Jing2
2021-12-08 0:03 ` [PATCH 14/19] x86/fpu: Prepare for KVM XFD_ERR handling Yang Zhong
2021-12-10 16:16 ` Paolo Bonzini
2021-12-10 23:20 ` Thomas Gleixner
2021-12-08 0:03 ` [PATCH 15/19] kvm: x86: Save and restore guest XFD_ERR properly Yang Zhong
2021-12-10 16:23 ` Paolo Bonzini
2021-12-10 22:01 ` Paolo Bonzini
2021-12-12 13:10 ` Yang Zhong
2021-12-11 0:10 ` Thomas Gleixner
2021-12-11 1:31 ` Paolo Bonzini
2021-12-11 3:23 ` Tian, Kevin
2021-12-11 13:10 ` Thomas Gleixner
2021-12-11 3:07 ` Tian, Kevin
2021-12-11 13:29 ` Thomas Gleixner
2021-12-12 1:50 ` Tian, Kevin
2021-12-12 9:10 ` Paolo Bonzini
2021-12-08 0:03 ` [PATCH 16/19] kvm: x86: Introduce KVM_{G|S}ET_XSAVE2 ioctl Yang Zhong
2021-12-10 16:25 ` Paolo Bonzini
2021-12-10 16:30 ` Paolo Bonzini
2021-12-10 22:13 ` Paolo Bonzini
2021-12-13 8:23 ` Wang, Wei W
2021-12-13 9:24 ` Paolo Bonzini
2021-12-14 6:06 ` Wang, Wei W
2021-12-14 6:18 ` Paolo Bonzini
2021-12-15 2:39 ` Wang, Wei W
2021-12-15 13:42 ` Paolo Bonzini
2021-12-16 8:25 ` Wang, Wei W
2021-12-16 10:28 ` Paolo Bonzini
2021-12-20 17:54 ` State Component 18 and Palette 1 (Re: [PATCH 16/19] kvm: x86: Introduce KVM_{G|S}ET_XSAVE2 ioctl) Nakajima, Jun
2021-12-22 14:44 ` Paolo Bonzini
2021-12-22 23:47 ` Nakajima, Jun
2021-12-22 14:52 ` Dave Hansen
2021-12-22 23:51 ` Nakajima, Jun
2021-12-13 10:10 ` [PATCH 16/19] kvm: x86: Introduce KVM_{G|S}ET_XSAVE2 ioctl Thomas Gleixner
2021-12-13 10:43 ` Paolo Bonzini
2021-12-13 12:40 ` Thomas Gleixner
2021-12-08 0:03 ` [PATCH 17/19] docs: virt: api.rst: Document the new KVM_{G, S}ET_XSAVE2 ioctls Yang Zhong
2021-12-08 0:03 ` [PATCH 18/19] kvm: x86: AMX XCR0 support for guest Yang Zhong
2021-12-10 16:30 ` Paolo Bonzini
2021-12-08 0:03 ` [PATCH 19/19] kvm: x86: Add AMX CPUIDs support Yang Zhong
2021-12-10 21:52 ` Paolo Bonzini
2021-12-11 21:20 ` [PATCH 00/19] AMX Support in KVM Thomas Gleixner
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