Re: [PATCHv7 5/8] kvm: eoi msi documentation

Avi Kivity
2012-06-18T14:20:23Z

On 06/14/2012 04:53 PM, Michael S. Tsirkin wrote:
> Document the new EOI MSR. Couldn't decide whether this change belongs
> conceptually on guest or host side, so a separate patch.
>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> Documentation/virtual/kvm/msr.txt | 32 ++++++++++++++++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt
> index 96b41bd..6ae5a85 100644
> --- a/Documentation/virtual/kvm/msr.txt
> +++ b/Documentation/virtual/kvm/msr.txt
> @@ -223,3 +223,35 @@ MSR_KVM_STEAL_TIME: 0x4b564d03
> steal: the amount of time in which this vCPU did not run, in
> nanoseconds. Time during which the vcpu is idle, will not be
> reported as steal time.
> +
> +MSR_KVM_EOI_EN: 0x4b564d04
> + data: Bit 0 is 1 when PV end of interrupt is enabled on the vcpu; 0
> + when disabled. When enabled, bits 63-1 hold 2-byte aligned physical address
> + of a 2 byte memory area which must be in guest RAM and must be zeroed.

2 byte aligned means we must never access it on the host with a >2 byte
instruction, or we risk touching unmapped memory.

--
error compiling committee.c: too many arguments to function