From: Paolo Bonzini <pbonzini@redhat.com>
To: Steve Rutherford <srutherford@google.com>
Cc: kvm@vger.kernel.org
Subject: Re: [PATCH v3 4/4] KVM: x86: Add support for local interrupt requests from userspace
Date: Fri, 26 Jun 2015 10:49:09 +0200 [thread overview]
Message-ID: <558D1205.8020601@redhat.com> (raw)
In-Reply-To: <20150626002609.GA15825@google.com>
On 26/06/2015 02:26, Steve Rutherford wrote:
> Implemented a basic version of this, and ran into some potential
> issues with this strategy. Supporting PIC masking/unmasking by the
> CPU/APIC means that either:
> A) PIC interrupts need to be bufferable in the kernel (with some way
> of comparing priorities).
> B) the APIC state needs to be read in order to fetch the bit as to
> whether or not the PIC is being masked (which I believe can be done
> from userspace via the APIC state ioctl).
> C) something hacky that doesn't conform to the PIC spec but still
> happens to boot common OSes (like buffering the interrupts and
> injecting them in the order of arrival (which is wrong)).
I think B is okay to do. Later if needed we can make it possible for
userspace to mmap the LAPIC page instead of using the APIC state ioctl.
Paolo
next prev parent reply other threads:[~2015-06-26 8:49 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-02 23:51 [PATCH v3 1/4] KVM: x86: Split the APIC from the rest of IRQCHIP Steve Rutherford
2015-06-02 23:51 ` [PATCH v3 2/4] KVM: x86: Add KVM exit for IOAPIC EOIs Steve Rutherford
2015-06-03 9:16 ` Paolo Bonzini
2015-06-02 23:51 ` [PATCH v3 3/4] KVM: x86: Add EOI exit bitmap inference Steve Rutherford
2015-06-03 9:16 ` Paolo Bonzini
2015-06-04 20:39 ` Steve Rutherford
2015-06-08 10:33 ` Wanpeng Li
2015-06-08 14:15 ` Paolo Bonzini
2015-06-09 2:16 ` Wanpeng Li
2015-06-17 8:14 ` Paolo Bonzini
2015-06-02 23:51 ` [PATCH v3 4/4] KVM: x86: Add support for local interrupt requests from userspace Steve Rutherford
2015-06-03 9:38 ` Paolo Bonzini
2015-06-04 20:21 ` Steve Rutherford
2015-06-20 0:41 ` Steve Rutherford
2015-06-21 20:10 ` Paolo Bonzini
2015-06-26 0:26 ` Steve Rutherford
2015-06-26 8:49 ` Paolo Bonzini [this message]
2015-06-03 8:54 ` [PATCH v3 1/4] KVM: x86: Split the APIC from the rest of IRQCHIP Paolo Bonzini
2015-06-04 20:38 ` Steve Rutherford
2015-06-05 7:19 ` Paolo Bonzini
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