From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
x86@kernel.org, linux-arch@vger.kernel.org,
Will Deacon <will@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Mark Rutland <mark.rutland@arm.com>,
Kees Cook <keescook@chromium.org>,
Keno Fischer <keno@juliacomputing.com>,
Paolo Bonzini <pbonzini@redhat.com>,
kvm@vger.kernel.org,
Gabriel Krisman Bertazi <krisman@collabora.com>
Subject: Re: [patch V5 15/15] x86/kvm: Use generic xfer to guest work function
Date: Thu, 23 Jul 2020 17:17:36 -0700 [thread overview]
Message-ID: <20200724001736.GK21891@linux.intel.com> (raw)
In-Reply-To: <20200722220520.979724969@linutronix.de>
On Thu, Jul 23, 2020 at 12:00:09AM +0200, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
>
> Use the generic infrastructure to check for and handle pending work before
> transitioning into guest mode.
>
> This now handles TIF_NOTIFY_RESUME as well which was ignored so
> far. Handling it is important as this covers task work and task work will
> be used to offload the heavy lifting of POSIX CPU timers to thread context.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
> V5: Rename exit -> xfer
> ---
One nit/question below (though it's really about patch 5).
Reviewed-and-tested-by: Sean Christopherson <sean.j.christopherson@intel.com>
> @@ -8676,15 +8677,11 @@ static int vcpu_run(struct kvm_vcpu *vcp
> break;
> }
>
> - if (signal_pending(current)) {
> - r = -EINTR;
> - vcpu->run->exit_reason = KVM_EXIT_INTR;
> - ++vcpu->stat.signal_exits;
> - break;
> - }
> - if (need_resched()) {
> + if (xfer_to_guest_mode_work_pending()) {
> srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
> - cond_resched();
> + r = xfer_to_guest_mode(vcpu);
Any reason not to call this xfer_to_guest_mode_work()? Or handle_work(),
do_work(), etc... Without the "work" part, it looks like a function that
should be invoked unconditionally. It's obvious that's not the case if
one looks at the implementation, but it's a bit confusing on the KVM side
of things.
> + if (r)
> + return r;
> vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
> }
> }
>
next prev parent reply other threads:[~2020-07-24 0:17 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-22 21:59 [patch V5 00/15] entry, x86, kvm: Generic entry/exit functionality for host and guest Thomas Gleixner
2020-07-22 21:59 ` Thomas Gleixner
2020-07-22 21:59 ` [patch V5 01/15] seccomp: Provide stub for __secure_computing() Thomas Gleixner
2020-07-22 21:59 ` Thomas Gleixner
2020-07-22 21:59 ` [patch V5 02/15] entry: Provide generic syscall entry functionality Thomas Gleixner
2020-07-22 21:59 ` Thomas Gleixner
2020-07-22 21:59 ` [patch V5 03/15] entry: Provide generic syscall exit function Thomas Gleixner
2020-07-22 21:59 ` [patch V5 04/15] entry: Provide generic interrupt entry/exit code Thomas Gleixner
2020-07-22 21:59 ` Thomas Gleixner
2020-07-22 21:59 ` [patch V5 05/15] entry: Provide infrastructure for work before transitioning to guest mode Thomas Gleixner
2020-07-29 16:55 ` Qian Cai
2020-07-29 16:55 ` Qian Cai
2020-07-30 7:19 ` Thomas Gleixner
2020-07-22 22:00 ` [patch V5 06/15] x86/entry: Consolidate check_user_regs() Thomas Gleixner
2020-07-22 22:00 ` Thomas Gleixner
2020-07-22 22:00 ` [patch V5 07/15] x86/entry: Consolidate 32/64 bit syscall entry Thomas Gleixner
2020-07-22 22:00 ` [patch V5 08/15] x86/entry: Move user return notifier out of loop Thomas Gleixner
2020-07-23 23:41 ` Sean Christopherson
2020-07-22 22:00 ` [patch V5 09/15] x86/ptrace: Provide pt_regs helper for entry/exit Thomas Gleixner
2020-07-22 22:00 ` [patch V5 10/15] x86/entry: Use generic syscall entry function Thomas Gleixner
2020-07-22 22:00 ` Thomas Gleixner
2020-07-22 22:00 ` [patch V5 11/15] x86/entry: Use generic syscall exit functionality Thomas Gleixner
2020-07-22 22:00 ` Thomas Gleixner
2020-07-22 22:00 ` [patch V5 12/15] x86/entry: Cleanup idtentry_entry/exit_user Thomas Gleixner
2020-07-22 22:00 ` Thomas Gleixner
2020-07-22 22:00 ` [patch V5 13/15] x86/entry: Use generic interrupt entry/exit code Thomas Gleixner
2020-07-22 22:00 ` Thomas Gleixner
2020-07-24 14:28 ` Ingo Molnar
2020-07-22 22:00 ` [patch V5 14/15] x86/entry: Cleanup idtentry_enter/exit Thomas Gleixner
2020-07-22 22:00 ` [patch V5 15/15] x86/kvm: Use generic xfer to guest work function Thomas Gleixner
2020-07-24 0:17 ` Sean Christopherson [this message]
2020-07-24 0:46 ` Thomas Gleixner
2020-07-24 0:55 ` Sean Christopherson
2020-07-24 14:24 ` Ingo Molnar
2020-07-24 19:08 ` Thomas Gleixner
2020-07-24 20:51 ` [patch V5 00/15] entry, x86, kvm: Generic entry/exit functionality for host and guest Thomas Gleixner
2020-07-24 20:51 ` Thomas Gleixner
2020-07-29 13:39 ` Steven Price
2020-07-29 13:39 ` Steven Price
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