From 88bd0e34db0df23164ca5b34e461cdfd646d1e39 Mon Sep 17 00:00:00 2001
From: Xiao Wang <jasowang@redhat.com>
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 <vyasevic@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Michael S. Tsirkin <mst@redhat.com>
From: "Michael S. Tsirkin" <mst@redhat.com>
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 <mst@redhat.com>
(cherry picked from commit 5f456073aa9ba54e421aa82dd38e4d40d0a0af85)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
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