Messages in this thread | | | Date | Tue, 05 Jan 2010 10:59:42 -0500 | From | Rik van Riel <> | Subject | Re: [PATCH v3 00/12] KVM: Add host swap event notifications for PV guest |
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On 01/05/2010 10:05 AM, Jun Koi wrote: > On Tue, Jan 5, 2010 at 11:12 PM, Gleb Natapov<gleb@redhat.com> wrote: >> KVM virtualizes guest memory by means of shadow pages or HW assistance >> like NPT/EPT. Not all memory used by a guest is mapped into the guest >> address space or even present in a host memory at any given time. >> When vcpu tries to access memory page that is not mapped into the guest >> address space KVM is notified about it. KVM maps the page into the guest >> address space and resumes vcpu execution. If the page is swapped out >> from host memory vcpu execution is suspended till the page is not swapped >> into the memory again. This is inefficient since vcpu can do other work >> (run other task or serve interrupts) while page gets swapped in. >> >> To overcome this inefficiency this patch series implements "asynchronous >> page fault" for paravirtualized KVM guests. If a page that vcpu is >> trying to access is swapped out KVM sends an async PF to the vcpu >> and continues vcpu execution. Requested page is swapped in by another >> thread in parallel. When vcpu gets async PF it puts faulted task to >> sleep until "wake up" interrupt is delivered. When the page is brought >> to the host memory KVM sends "wake up" interrupt and the guest's task >> resumes execution. >> > > Is it true that to make this work, we will need a (PV) kernel driver > for each guest OS (Windows, Linux, ...)?
This patch series contains the guest kernel code for Linux, as well as the host side code.
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