Re: [PATCH] kvm: fix MMIO/PIO collision misdetection

From: Gleb Natapov
Date: Sun Apr 07 2013 - 07:54:15 EST


On Thu, Apr 04, 2013 at 01:27:21PM +0300, Michael S. Tsirkin wrote:
> PIO and MMIO are separate address spaces, but
> ioeventfd registration code mistakenly detected
> two eventfds as duplicate if they use the same address,
> even if one is PIO and another one MMIO.
>
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Applied, thanks.

> ---
> virt/kvm/eventfd.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
> index adb17f2..93e5b05 100644
> --- a/virt/kvm/eventfd.c
> +++ b/virt/kvm/eventfd.c
> @@ -577,6 +577,7 @@ struct _ioeventfd {
> struct eventfd_ctx *eventfd;
> u64 datamatch;
> struct kvm_io_device dev;
> + u8 bus_idx;
> bool wildcard;
> };
>
> @@ -669,7 +670,8 @@ ioeventfd_check_collision(struct kvm *kvm, struct _ioeventfd *p)
> struct _ioeventfd *_p;
>
> list_for_each_entry(_p, &kvm->ioeventfds, list)
> - if (_p->addr == p->addr && _p->length == p->length &&
> + if (_p->bus_idx == p->bus_idx &&
> + _p->addr == p->addr && _p->length == p->length &&
> (_p->wildcard || p->wildcard ||
> _p->datamatch == p->datamatch))
> return true;
> @@ -717,6 +719,7 @@ kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
>
> INIT_LIST_HEAD(&p->list);
> p->addr = args->addr;
> + p->bus_idx = bus_idx;
> p->length = args->len;
> p->eventfd = eventfd;
>
> @@ -775,7 +778,8 @@ kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
> list_for_each_entry_safe(p, tmp, &kvm->ioeventfds, list) {
> bool wildcard = !(args->flags & KVM_IOEVENTFD_FLAG_DATAMATCH);
>
> - if (p->eventfd != eventfd ||
> + if (p->bus_idx != bus_idx ||
> + p->eventfd != eventfd ||
> p->addr != args->addr ||
> p->length != args->len ||
> p->wildcard != wildcard)
> --
> MST

--
Gleb.
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