From 5f456073aa9ba54e421aa82dd38e4d40d0a0af85 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Wed, 22 Jul 2015 13:09:25 +0300 Subject: [PATCH] virtio: hide legacy features from modern guests 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 --- 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 283401aa0d..db8f27c100 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -1095,7 +1095,8 @@ 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 473fb75e28..0634c15ab0 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, -- GitLab