From bd83a3df8308ed5f55f7e43a6b135b2333384bb9 Mon Sep 17 00:00:00 2001
From: Michael S. Tsirkin <mst@redhat.com>
Date: Tue, 12 Apr 2011 13:14:45 -0300
Subject: [RHEL6 qemu-kvm PATCH 1/7] bz 691704: vhost: skip VGA memory regions
RH-Author: Michael S. Tsirkin <mst@redhat.com>
Message-id: <20110412131445.GA12694@redhat.com>
Patchwork-id: 21958
O-Subject: [PATCH RHEL6.1] bz 691704: vhost: skip VGA memory regions
Bugzilla: 691704
RH-Acked-by: Alex Williamson <alex.williamson@redhat.com>
RH-Acked-by: Gleb Natapov <gleb@redhat.com>
RH-Acked-by: Avi Kivity <avi@redhat.com>
There's no good reason for vhost-net to DMA into the VGA region,
and even if we did, vhost doesn't support write logging
(except for migration), anyway.
Avi suggested this simpler work around as lower-risk and
more maintainable given 6.1 schedule.
Upstream: N/A
Bugzilla: 691704
Brew build: 3251216
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
hw/vhost.c | 10 ++++++++++
1 files changed, 10 insertions(+), 0 deletions(-)
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
hw/vhost.c | 10 ++++++++++
1 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/hw/vhost.c b/hw/vhost.c
index 97a1299..6dffa2b 100644
--- a/hw/vhost.c
+++ b/hw/vhost.c
@@ -310,6 +310,16 @@ static void vhost_client_set_memory(CPUPhysMemoryClient *client,
(dev->mem->nregions + 1) * sizeof dev->mem->regions[0];
uint64_t log_size;
int r;
+
+ /* TODO: this is a hack.
+ * At least one vga card (cirrus) changes the gpa to hva
+ * memory maps on data path, which slows us down.
+ * Since we should never need to DMA into VGA memory
+ * anyway, lets just skip these regions. */
+ if (ranges_overlap(start_addr, size, 0xa0000, 0x10000)) {
+ return;
+ }
+
dev->mem = qemu_realloc(dev->mem, s);
assert(size);
--
1.7.3.2