From 88bd0e34db0df23164ca5b34e461cdfd646d1e39 Mon Sep 17 00:00:00 2001 From: Xiao Wang Date: Mon, 10 Aug 2015 05:09:25 +0200 Subject: [PATCH 04/16] virtio: hide legacy features from modern guests Message-id: <1439183375-4841-5-git-send-email-jasowang@redhat.com> Patchwork-id: 67431 O-Subject: [RHEL7.2 qemu-kvm-rhev PATCH 04/14] virtio: hide legacy features from modern guests Bugzilla: 1248312 RH-Acked-by: Vlad Yasevich RH-Acked-by: Paolo Bonzini RH-Acked-by: Michael S. Tsirkin From: "Michael S. Tsirkin" NOTIFY_ON_EMPTY, ANY_LAYOUT and BAD are only valid on the legacy interface. Hide them from modern guests. Signed-off-by: Michael S. Tsirkin (cherry picked from commit 5f456073aa9ba54e421aa82dd38e4d40d0a0af85) Signed-off-by: Miroslav Rezanina --- hw/virtio/virtio-pci.c | 3 ++- include/hw/virtio/virtio.h | 4 ++++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index e2e1eb5..c8bf6b9 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -970,7 +970,8 @@ static uint64_t virtio_pci_common_read(void *opaque, hwaddr addr, break; case VIRTIO_PCI_COMMON_DF: if (proxy->dfselect <= 1) { - val = vdev->host_features >> (32 * proxy->dfselect); + val = (vdev->host_features & ~VIRTIO_LEGACY_FEATURES) >> + (32 * proxy->dfselect); } break; case VIRTIO_PCI_COMMON_GFSELECT: diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 2bf9cc1..48f0377 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virtio.h @@ -25,6 +25,10 @@ /* A guest should never accept this. It implies negotiation is broken. */ #define VIRTIO_F_BAD_FEATURE 30 +#define VIRTIO_LEGACY_FEATURES ((0x1ULL << VIRTIO_F_BAD_FEATURE) | \ + (0x1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | \ + (0x1ULL << VIRTIO_F_ANY_LAYOUT)) + struct VirtQueue; static inline hwaddr vring_align(hwaddr addr, -- 1.8.3.1