[PULL v2 0/6] virtio,pci: bugfixes

[PULL v2 0/6] virtio,pci: bugfixes

[Michael S. Tsirkin]

v2 due to issues noticed by dgilbert in v1.
Changes from v1:
    dropped a work around for pci migration for old machine types.


The following changes since commit 4215d3413272ad6d1c6c9d0234450b602e46a74c:

  Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-5.1-20200727' into staging (2020-07-27 09:33:04 +0100)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/virt/kvm/mst/qemu.git tags/for_upstream

for you to fetch changes up to d0d89526f70ded5ac41a4c6bb071c0d919b772db:

  MAINTAINERS: Cover the firmware JSON schema (2020-07-27 10:28:28 -0400)

----------------------------------------------------------------
virtio,pci: bugfixes

Minor bugfixes all over the places, including one CVE.

Additionally, a fix for an ancient bug in migration -
one has to wonder how come no one noticed.

The fix is also non-trivial since we dare not break all
existing machine types with pci - we have a work around
in the works, for now we just skip the work-around for
old machine types.

Great job by Hogan Wang noticing, debugging and fixing it,
and thanks to Dr. David Alan Gilbert for reviewing the patches.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

----------------------------------------------------------------
Cindy Lu (1):
      vhost-vdpa :Fix Coverity CID 1430270 / CID 1420267

David Hildenbrand (1):
      virtio-mem-pci: force virtio version 1

Hogan Wang (1):
      hw/pci-host: save/restore pci host config register

Philippe Mathieu-Daudé (2):
      libvhost-user: Report descriptor index on panic
      MAINTAINERS: Cover the firmware JSON schema

Raphael Norwitz (1):
      Fix vhost-user buffer over-read on ram hot-unplug

 include/hw/pci/pci_host.h             |  1 +
 contrib/libvhost-user/libvhost-user.c |  4 ++--
 hw/core/machine.c                     |  1 +
 hw/i386/pc.c                          |  3 ++-
 hw/pci/pci_host.c                     | 33 +++++++++++++++++++++++++++++++++
 hw/virtio/vhost-user.c                |  2 +-
 hw/virtio/vhost-vdpa.c                |  4 ++--
 hw/virtio/virtio-mem-pci.c            |  4 ++--
 MAINTAINERS                           |  8 ++++++++
 9 files changed, 52 insertions(+), 8 deletions(-)

[PULL v2 1/6] virtio-mem-pci: force virtio version 1

[Michael S. Tsirkin]

From: David Hildenbrand <david@redhat.com>

Trying to run simple virtio-mem-pci examples currently fails with
    qemu-system-x86_64: -device virtio-mem-pci,id=vm0,memdev=mem0,node=0,
    requested-size=300M: device is modern-only, use disable-legacy=on
due to the added safety checks in 9b3a35ec8236 ("virtio: verify that legacy
support is not accidentally on").

As noted by Conny, we have to force virtio version 1. While at it, use
qdev_realize() to set the parent bus and realize - like most other
virtio-*-pci implementations.

Fixes: 0b9a2443a48b ("virtio-pci: Proxy for virtio-mem")
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200727115905.129397-1-david@redhat.com>
Cc: qemu-stable@nongnu.org
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/virtio/virtio-mem-pci.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/virtio-mem-pci.c b/hw/virtio/virtio-mem-pci.c
index d375280ee1..590cec041b 100644
--- a/hw/virtio/virtio-mem-pci.c
+++ b/hw/virtio/virtio-mem-pci.c
@@ -21,8 +21,8 @@ static void virtio_mem_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
     VirtIOMEMPCI *mem_pci = VIRTIO_MEM_PCI(vpci_dev);
     DeviceState *vdev = DEVICE(&mem_pci->vdev);
 
-    qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
-    object_property_set_bool(OBJECT(vdev), "realized", true, errp);
+    virtio_pci_force_virtio_1(vpci_dev);
+    qdev_realize(vdev, BUS(&vpci_dev->bus), errp);
 }
 
 static void virtio_mem_pci_set_addr(MemoryDeviceState *md, uint64_t addr,
-- 
MST

[PULL v2 2/6] hw/pci-host: save/restore pci host config register

[Michael S. Tsirkin]

From: Hogan Wang <king.wang@huawei.com>

The pci host config register is used to save PCI address for
read/write config data. If guest writes a value to config register,
and then QEMU pauses the vcpu to migrate, after the migration, the guest
will continue to write pci config data, and the write data will be ignored
because of new qemu process losing the config register state.

To trigger the bug:
1. guest is booting in seabios.
2. guest enables the SMRAM in seabios:piix4_apmc_smm_setup, and then
   expects to disable the SMRAM by pci_config_writeb.
3. after guest writes the pci host config register, QEMU pauses vcpu
   to finish migration.
4. guest write of config data(0x0A) fails to disable the SMRAM because
   the config register state is lost.
5. guest continues to boot and crashes in ipxe option ROM due to SMRAM
   in enabled state.

Example Reproducer:

step 1. Make modifications to seabios and qemu for increase reproduction
efficiency, write 0xf0 to 0x402 port notify qemu to stop vcpu after
0x0cf8 port wrote i440 configure register. qemu stop vcpu when catch
0x402 port wrote 0xf0.

seabios:/src/hw/pci.c
@@ -52,6 +52,11 @@ void pci_config_writeb(u16 bdf, u32 addr, u8 val)
         writeb(mmconfig_addr(bdf, addr), val);
     } else {
         outl(ioconfig_cmd(bdf, addr), PORT_PCI_CMD);
+       if (bdf == 0 && addr == 0x72 && val == 0xa) {
+            dprintf(1, "stop vcpu\n");
+            outb(0xf0, 0x402); // notify qemu to stop vcpu
+            dprintf(1, "resume vcpu\n");
+        }
         outb(val, PORT_PCI_DATA + (addr & 3));
     }
 }

qemu:hw/char/debugcon.c
@@ -60,6 +61,9 @@ static void debugcon_ioport_write(void *opaque, hwaddr addr, uint64_t val,
     printf(" [debugcon: write addr=0x%04" HWADDR_PRIx " val=0x%02" PRIx64 "]\n", addr, val);
 #endif

+    if (ch == 0xf0) {
+        vm_stop(RUN_STATE_PAUSED);
+    }
     /* XXX this blocks entire thread. Rewrite to use
      * qemu_chr_fe_write and background I/O callbacks */
     qemu_chr_fe_write_all(&s->chr, &ch, 1);

step 2. start vm1 by the following command line, and then vm stopped.
$ qemu-system-x86_64 -machine pc-i440fx-5.0,accel=kvm\
 -netdev tap,ifname=tap-test,id=hostnet0,vhost=on,downscript=no,script=no\
 -device virtio-net-pci,netdev=hostnet0,id=net0,bus=pci.0,addr=0x13,bootindex=3\
 -device cirrus-vga,id=video0,vgamem_mb=16,bus=pci.0,addr=0x2\
 -chardev file,id=seabios,path=/var/log/test.seabios,append=on\
 -device isa-debugcon,iobase=0x402,chardev=seabios\
 -monitor stdio

step 3. start vm2 to accept vm1 state.
$ qemu-system-x86_64 -machine pc-i440fx-5.0,accel=kvm\
 -netdev tap,ifname=tap-test1,id=hostnet0,vhost=on,downscript=no,script=no\
 -device virtio-net-pci,netdev=hostnet0,id=net0,bus=pci.0,addr=0x13,bootindex=3\
 -device cirrus-vga,id=video0,vgamem_mb=16,bus=pci.0,addr=0x2\
 -chardev file,id=seabios,path=/var/log/test.seabios,append=on\
 -device isa-debugcon,iobase=0x402,chardev=seabios\
 -monitor stdio \
 -incoming tcp:127.0.0.1:8000

step 4. execute the following qmp command in vm1 to migrate.
(qemu) migrate tcp:127.0.0.1:8000

step 5. execute the following qmp command in vm2 to resume vcpu.
(qemu) cont
Before this patch, we get KVM "emulation failure" error on vm2.
This patch fixes it.

Cc: qemu-stable@nongnu.org
Signed-off-by: Hogan Wang <hogan.wang@huawei.com>
Message-Id: <20200727084621.3279-1-hogan.wang@huawei.com>
Reported-by: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 include/hw/pci/pci_host.h |  1 +
 hw/core/machine.c         |  1 +
 hw/i386/pc.c              |  3 ++-
 hw/pci/pci_host.c         | 33 +++++++++++++++++++++++++++++++++
 4 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/include/hw/pci/pci_host.h b/include/hw/pci/pci_host.h
index 9ce088bd13..6210a7e14d 100644
--- a/include/hw/pci/pci_host.h
+++ b/include/hw/pci/pci_host.h
@@ -45,6 +45,7 @@ struct PCIHostState {
     MemoryRegion data_mem;
     MemoryRegion mmcfg;
     uint32_t config_reg;
+    bool mig_enabled;
     PCIBus *bus;
 
     QLIST_ENTRY(PCIHostState) next;
diff --git a/hw/core/machine.c b/hw/core/machine.c
index 2f881d6d75..8d1a90c6cf 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -29,6 +29,7 @@
 #include "migration/vmstate.h"
 
 GlobalProperty hw_compat_5_0[] = {
+    { "pci-host-bridge", "x-config-reg-migration-enabled", "off" },
     { "virtio-balloon-device", "page-poison", "false" },
     { "vmport", "x-read-set-eax", "off" },
     { "vmport", "x-signal-unsupported-cmd", "off" },
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 3d419d5991..47c5ca3e34 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -97,7 +97,8 @@
 #include "fw_cfg.h"
 #include "trace.h"
 
-GlobalProperty pc_compat_5_0[] = {};
+GlobalProperty pc_compat_5_0[] = {
+};
 const size_t pc_compat_5_0_len = G_N_ELEMENTS(pc_compat_5_0);
 
 GlobalProperty pc_compat_4_2[] = {
diff --git a/hw/pci/pci_host.c b/hw/pci/pci_host.c
index ce7bcdb1d5..8ca5fadcbd 100644
--- a/hw/pci/pci_host.c
+++ b/hw/pci/pci_host.c
@@ -22,8 +22,10 @@
 #include "hw/pci/pci.h"
 #include "hw/pci/pci_bridge.h"
 #include "hw/pci/pci_host.h"
+#include "hw/qdev-properties.h"
 #include "qemu/module.h"
 #include "hw/pci/pci_bus.h"
+#include "migration/vmstate.h"
 #include "trace.h"
 
 /* debug PCI */
@@ -200,12 +202,43 @@ const MemoryRegionOps pci_host_data_be_ops = {
     .endianness = DEVICE_BIG_ENDIAN,
 };
 
+static bool pci_host_needed(void *opaque)
+{
+    PCIHostState *s = opaque;
+    return s->mig_enabled;
+}
+
+const VMStateDescription vmstate_pcihost = {
+    .name = "PCIHost",
+    .needed = pci_host_needed,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(config_reg, PCIHostState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static Property pci_host_properties_common[] = {
+    DEFINE_PROP_BOOL("x-config-reg-migration-enabled", PCIHostState,
+                     mig_enabled, true),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void pci_host_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    device_class_set_props(dc, pci_host_properties_common);
+    dc->vmsd = &vmstate_pcihost;
+}
+
 static const TypeInfo pci_host_type_info = {
     .name = TYPE_PCI_HOST_BRIDGE,
     .parent = TYPE_SYS_BUS_DEVICE,
     .abstract = true,
     .class_size = sizeof(PCIHostBridgeClass),
     .instance_size = sizeof(PCIHostState),
+    .class_init = pci_host_class_init,
 };
 
 static void pci_host_register_types(void)
-- 
MST

[PULL v2 3/6] Fix vhost-user buffer over-read on ram hot-unplug

[Michael S. Tsirkin]

From: Raphael Norwitz <raphael.norwitz@nutanix.com>

The VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS vhost-user protocol
feature introduced a shadow-table, used by the backend to dynamically
determine how a vdev's memory regions have changed since the last
vhost_user_set_mem_table() call. On hot-remove, a memmove() operation
is used to overwrite the removed shadow region descriptor(s). The size
parameter of this memmove was off by 1 such that if a VM with a backend
supporting the VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS filled it's
shadow-table (by performing the maximum number of supported hot-add
operatons) and attempted to remove the last region, Qemu would read an
out of bounds value and potentially crash.

This change fixes the memmove() bounds such that this erroneous read can
never happen.

Signed-off-by: Peter Turschmid <peter.turschm@nutanix.com>
Signed-off-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <1594799958-31356-1-git-send-email-raphael.norwitz@nutanix.com>
Fixes: f1aeb14b0809 ("Transmit vhost-user memory regions individually")
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Cc: qemu-stable@nongnu.org
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/virtio/vhost-user.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 31231218dc..d7e2423762 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -672,7 +672,7 @@ static int send_remove_regions(struct vhost_dev *dev,
         memmove(&u->shadow_regions[shadow_reg_idx],
                 &u->shadow_regions[shadow_reg_idx + 1],
                 sizeof(struct vhost_memory_region) *
-                (u->num_shadow_regions - shadow_reg_idx));
+                (u->num_shadow_regions - shadow_reg_idx - 1));
         u->num_shadow_regions--;
     }
 
-- 
MST

[PULL v2 4/6] libvhost-user: Report descriptor index on panic

[Michael S. Tsirkin]

From: Philippe Mathieu-Daudé <philmd@redhat.com>

We want to report the index of the descriptor,
not its pointer.

Fixes: 7b2e5c65f4 ("contrib: add libvhost-user")
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200723171935.18535-1-philmd@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Cc: qemu-stable@nongnu.org
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 contrib/libvhost-user/libvhost-user.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
index d315db1396..53f16bdf08 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -2074,7 +2074,7 @@ virtqueue_get_head(VuDev *dev, VuVirtq *vq,
 
     /* If their number is silly, that's a fatal mistake. */
     if (*head >= vq->vring.num) {
-        vu_panic(dev, "Guest says index %u is available", head);
+        vu_panic(dev, "Guest says index %u is available", *head);
         return false;
     }
 
@@ -2133,7 +2133,7 @@ virtqueue_read_next_desc(VuDev *dev, struct vring_desc *desc,
     smp_wmb();
 
     if (*next >= max) {
-        vu_panic(dev, "Desc next is %u", next);
+        vu_panic(dev, "Desc next is %u", *next);
         return VIRTQUEUE_READ_DESC_ERROR;
     }
 
-- 
MST

[PULL v2 5/6] vhost-vdpa :Fix Coverity CID 1430270 / CID 1420267

[Michael S. Tsirkin]

From: Cindy Lu <lulu@redhat.com>

In the function vhost_vdpa_dma_map/unmap, The struct msg was not initialized all its fields.

Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20200710064642.24505-1-lulu@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Cc: qemu-stable@nongnu.org
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/virtio/vhost-vdpa.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 65d5aaf08a..4580f3efd8 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -37,7 +37,7 @@ static bool vhost_vdpa_listener_skipped_section(MemoryRegionSection *section)
 static int vhost_vdpa_dma_map(struct vhost_vdpa *v, hwaddr iova, hwaddr size,
                               void *vaddr, bool readonly)
 {
-    struct vhost_msg_v2 msg;
+    struct vhost_msg_v2 msg = {};
     int fd = v->device_fd;
     int ret = 0;
 
@@ -60,7 +60,7 @@ static int vhost_vdpa_dma_map(struct vhost_vdpa *v, hwaddr iova, hwaddr size,
 static int vhost_vdpa_dma_unmap(struct vhost_vdpa *v, hwaddr iova,
                                 hwaddr size)
 {
-    struct vhost_msg_v2 msg;
+    struct vhost_msg_v2 msg = {};
     int fd = v->device_fd;
     int ret = 0;
 
-- 
MST

[PULL v2 6/6] MAINTAINERS: Cover the firmware JSON schema

[Michael S. Tsirkin]

From: Philippe Mathieu-Daudé <philmd@redhat.com>

Add an entry to cover firmware.json (see commit 3a0adfc9bf:
schema that describes the different uses and properties of
virtual machine firmware).

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Kashyap Chamarthy <kchamart@redhat.com>
Cc: Daniel P. Berrange <berrange@redhat.com>
Suggested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200703183450.32398-1-philmd@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Kashyap Chamarthy <kchamart@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 MAINTAINERS | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 3395abd4e1..0886eb3d2b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2667,6 +2667,14 @@ F: include/hw/i2c/smbus_master.h
 F: include/hw/i2c/smbus_slave.h
 F: include/hw/i2c/smbus_eeprom.h
 
+Firmware schema specifications
+M: Laszlo Ersek <lersek@redhat.com>
+M: Philippe Mathieu-Daudé <philmd@redhat.com>
+R: Daniel P. Berrange <berrange@redhat.com>
+R: Kashyap Chamarthy <kchamart@redhat.com>
+S: Maintained
+F: docs/interop/firmware.json
+
 EDK2 Firmware
 M: Laszlo Ersek <lersek@redhat.com>
 M: Philippe Mathieu-Daudé <philmd@redhat.com>
-- 
MST

Re: [PULL v2 0/6] virtio,pci: bugfixes

[Peter Maydell]

On Mon, 27 Jul 2020 at 15:32, Michael S. Tsirkin <mst@redhat.com> wrote:
>
> v2 due to issues noticed by dgilbert in v1.
> Changes from v1:
>     dropped a work around for pci migration for old machine types.
>
>
> The following changes since commit 4215d3413272ad6d1c6c9d0234450b602e46a74c:
>
>   Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-5.1-20200727' into staging (2020-07-27 09:33:04 +0100)
>
> are available in the Git repository at:
>
>   git://git.kernel.org/pub/scm/virt/kvm/mst/qemu.git tags/for_upstream
>
> for you to fetch changes up to d0d89526f70ded5ac41a4c6bb071c0d919b772db:
>
>   MAINTAINERS: Cover the firmware JSON schema (2020-07-27 10:28:28 -0400)
>
> ----------------------------------------------------------------
> virtio,pci: bugfixes
>
> Minor bugfixes all over the places, including one CVE.
>
> Additionally, a fix for an ancient bug in migration -
> one has to wonder how come no one noticed.
>
> The fix is also non-trivial since we dare not break all
> existing machine types with pci - we have a work around
> in the works, for now we just skip the work-around for
> old machine types.
>
> Great job by Hogan Wang noticing, debugging and fixing it,
> and thanks to Dr. David Alan Gilbert for reviewing the patches.
>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
>


Applied, thanks.

Please update the changelog at https://wiki.qemu.org/ChangeLog/5.1
for any user-visible changes.

-- PMM