From: Paolo Bonzini <pbonzini@redhat.com>
To: Wanpeng Li <kernellwp@gmail.com>
Cc: "Charls D. Chap" <chapcharls@gmail.com>, kvm <kvm@vger.kernel.org>
Subject: Re: tlb flush after each vm_exit, also virtual interrupts injection
Date: Mon, 29 Aug 2016 11:55:43 +0200 [thread overview]
Message-ID: <be4afab0-2dba-02fc-b96a-335a5a5819ed@redhat.com> (raw)
In-Reply-To: <CANRm+CyLaK1+6J3VN9RNtG7AD6OGr_sb1unUVT0O=XGNtJQTTQ@mail.gmail.com>
On 25/08/2016 11:12, Wanpeng Li wrote:
>> >
>> > ioctl when? interrupt kind
>> > ------------------------------------------------------------------------
>> > KVM_INTERRUPT i8259 in userspace EXTINT
>> > KVM_SET_GSI_ROUTING (always) IOAPIC
>> > KVM_SIGNAL_MSI (always) MSI
>> > KVM_SET_GSI_ROUTING (always) MSI
>> > KVM_IRQFD any that can use KVM_SET_GSI_ROUTING
>> >
>> > After KVM_SET_GSI_ROUTING, the host invokes another ioctl on the VM
> MSI routing is also set by KVM_SET_GSI_ROUTING，though MSI/MSI-X
> doesn't associated with GSI, this is intended to save a KVM API,
> right? In addition, kvm_send_userspace_msi() which is called in
> KVM_SIGNAL_MSI path set MSI routing entry again,
No, kvm_send_userspace_msi simply converts the struct used by userspace
(struct kvm_msi) into the one used by the kernel (struct
kvm_kernel_irq_routing_entry).
I saw there are
> patches which will update gsi routing after changed MSI-X
> configuration(https://patchwork.kernel.org/patch/6827431/)
> , so why set MSI routing entry again during send MSI?
KVM_SIGNAL_MSI does not need a previous KVM_SET_GSI_ROUTING, but if
userspace wants it can use both. Note that you've linked a patch for
lkvm, not Linux or QEMU.
Paolo
next prev parent reply other threads:[~2016-08-29 9:55 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-27 10:19 tlb flush after each vm_exit, also virtual interrupts injection charls chap
2016-07-28 8:20 ` Fwd: " Charls D. Chap
2016-08-02 17:33 ` Paolo Bonzini
2016-08-03 14:43 ` Charls D. Chap
2016-08-03 15:56 ` Paolo Bonzini
2016-08-05 11:29 ` Charls D. Chap
2016-08-05 11:59 ` Paolo Bonzini
2016-08-25 9:12 ` Wanpeng Li
2016-08-29 9:55 ` Paolo Bonzini [this message]
2016-08-29 10:22 ` Wanpeng Li
2016-08-29 16:39 ` Paolo Bonzini
2016-08-30 0:39 ` Wanpeng Li
2016-07-28 13:25 ` Radim Krčmář
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