Improve the warnings we give if the user specified a combination of -net
options which don't make much sense:
* Don't warn about anything if the config is the implicit default
"-net user -net nic" rather than one specified by the user (this will
only kick in for boards with no NIC or if CONFIG_SLIRP is not set)
* Diagnose the case where the user asked for NICs which the board
didn't instantiate (for example where the user asked for two NICs
but the board only supports one)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Correct the condition determining whether we instantiate the onboard
NIC or a PCI card NIC on VersatilePB and Realview boards. This was broken
in two ways:
(1) if the user asked for two default NICs ("-net nic -net nic") we would
crash trying to strcmp() a NULL pointer
(2) if the user asked for two NICs explicitly of the same model as the
onboard NIC (eg "-net nic,model=smc91c111 -net nic,model=smc91c111")
we would try to instantiate two onboard NICs at the same address.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
The problem is with definitions in hw/pcnet.c such as:
#define CSR_CRDA(S) ((S)->csr[28] | ((S)->csr[29] << 16))
"(S)->csr[29]" is a uint16_t, but "(S)->csr[29] << 16" gets promoted to
int, so the overall CSR_CRDA(s) is a (signed) int rather than a uint32_t.
This then gets assigned to a uint64_t using
target_phys_addr_t crda = CSR_CRDA(s);
so when (S)->csr[29] has the high bit set, we end up with
crda=0xffffffffxxxxxxxx.
From: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Move the allocation and freeing of the TCG temp used for the address for
Neon load/store instructions so that we don't allocate the temporary
until we've done enough decoding to know that the instruction is not
an UNDEF pattern; this avoids leaking the TCG temp in these cases.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Fix several bugs in VLD of single element to all lanes:
The "single element to all lanes" form of VLD1 differs from those for
VLD2, VLD3 and VLD4 in that bit 5 indicates whether the loaded element
should be written to one or two Dregs (rather than being a register
stride). Handle this by special-casing VLD1 rather than trying to
have one loop which deals with both VLD1 and 2/3/4.
Handle VLD4.32 with 16 byte alignment specified, rather than UNDEFfing.
UNDEF for the invalid size and alignment combinations.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
There are no { name, keysym } values in name2keysym[] array for Polish
national characters so "-k pl" option has no effect.
Signed-off-by: Leszek Grzegorek <leszek.grzegorek@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
qemu now has generic bitmap functions,
so don't redefine them in sheepdog.c,
use common header instead. A small cleanup.
Here's only one function which is actually
used in sheepdog and gets replaced with
a generic one (simplified):
- static inline int test_bit(int nr, const volatile unsigned long *addr)
+ static inline int test_bit(int nr, const unsigned long *addr)
{
- return ((1UL << (nr % BITS_PER_LONG))
& ((unsigned long*)addr)[nr / BITS_PER_LONG])) != 0;
+ return 1UL & (addr[nr / BITS_PER_LONG] >> (nr & (BITS_PER_LONG-1)));
}
The body is equivalent, but the argument is not: there's
"volatile" in there. Why it is used for - I'm not sure.
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Acked-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
If these messages are not handled correctly the guest driver may hang.
Always mandatory:
- ABORT
- BUS DEVICE RESET
Mandatory if tagged queuing is implemented (which disks usually do):
- ABORT TAG
- CLEAR QUEUE
Signed-off-by: Bernhard Kohl <bernhard.kohl@nsn.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
I enable acpi_piix4 debug, and got the following build errors:
# make
CC libhw64/acpi_piix4.o
cc1: warnings being treated as errors
/home/wency/source/qemu/hw/acpi_piix4.c: In function ‘pm_ioport_write’:
/home/wency/source/qemu/hw/acpi_piix4.c:193: error: format ‘%04x’ expects type ‘unsigned int’, but argument 2 has type ‘uint64_t’
/home/wency/source/qemu/hw/acpi_piix4.c:193: error: format ‘%04x’ expects type ‘unsigned int’, but argument 3 has type ‘uint64_t’
/home/wency/source/qemu/hw/acpi_piix4.c: In function ‘pm_ioport_read’:
/home/wency/source/qemu/hw/acpi_piix4.c:219: error: format ‘%04x’ expects type ‘unsigned int’, but argument 2 has type ‘uint64_t’
make[1]: *** [acpi_piix4.o] Error 1
make: *** [subdir-libhw64] Error 2
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Load an optional QEMU icon file. If there is no icon file named
qemu.bmp in QEMU's default search path, QEMU will run with
the usual system default icon.
A matching icon file will be loaded and used by X Windows managers
or MS Windows while a QEMU instance is running.
SDL requires icon files in 32x32x4 bmp format.
Cc: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Currently, the emulated pSeries machine requires the use of the
-kernel parameter in order to explicitly load a guest kernel. This
means booting from the virtual disk, cdrom or network is not possible.
This patch addresses this limitation by inserting a within-partition
firmware image (derived from the "SLOF" free Open Firmware project).
If -kernel is not specified, qemu will now load the SLOF image, which
has access to the qemu boot device list through the device tree, and
can boot from any of the usual virtual devices.
In order to support the new firmware, an extension to the emulated
machine/hypervisor is necessary. Unlike Linux, which expects
multi-CPU entry to be handled kexec() style, the SLOF firmware expects
only one CPU to be active at entry, and to use a hypervisor RTAS
method to enable the other CPUs one by one.
This patch also implements this 'start-cpu' method, so that SLOF can
start the secondary CPUs and marshal them into the kexec() holding
pattern ready for entry into the guest OS. Linux should, and in the
future might directly use the start-cpu method to enable initially
disabled CPUs, but for now it does require kexec() entry.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Shared-processor partitions are those where a CPU is time-sliced between
partitions, rather than being permanently dedicated to a single
partition. qemu emulated partitions, since they are just scheduled with
the qemu user process, behave mostly like shared processor partitions.
In order to better support shared processor partitions (splpar), PAPR
defines the "VPA" (Virtual Processor Area), a shared memory communication
channel between the hypervisor and partitions. There are also two
additional shared memory communication areas for specialized purposes
associated with the VPA.
A VPA is not essential for operating an splpar, though it can be necessary
for obtaining accurate performance measurements in the presence of
runtime partition switching.
Most importantly, however, the VPA is a prerequisite for PAPR's H_CEDE,
hypercall, which allows a partition OS to give up it's shared processor
timeslices to other partitions when idle.
This patch implements the VPA and H_CEDE hypercalls in qemu. We don't
implement any of the more advanced statistics which can be communicated
through the VPA. However, this is enough to make normal pSeries kernels
do an effective power-save idle on an emulated pSeries, significantly
reducing the host load of a qemu emulated pSeries running an idle guest OS.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Usually, PAPR virtual IO devices use a virtual IOMMU mechanism, TCEs,
to mediate all DMA transfers. While this is necessary for some sorts of
operation, it can be complex to program and slow for others.
This patch implements a mechanism for bypassing TCE translation, treating
"IO" addresses as plain (guest) physical memory addresses. This has two
main uses:
* Simple, but 64-bit aware programs like firmwares can use the VIO devices
without the complexity of TCE setup.
* The guest OS can optionally use the TCE bypass to improve performance in
suitable situations.
The mechanism used is a per-device flag which disables TCE translation.
The flag is toggled with some (hypervisor-implemented) RTAS methods.
Signed-off-by: Ben Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This patch implements the infrastructure and hypercalls necessary for
the PAPR specified Virtual SCSI interface. This is the normal method
for providing (virtual) disks to PAPR partitions.
Signed-off-by: Ben Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This patch implements the infrastructure and hypercalls necessary for the
PAPR specified CRQ (Command Request Queue) mechanism. This general
request queueing system is used by many of the PAPR virtual IO devices,
including the virtual scsi adapter.
Signed-off-by: Ben Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This patch implements the PAPR specified Inter Virtual Machine Logical
LAN; that is the virtual hardware used by the Linux ibmveth driver.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This patch implements the necessary infrastructure and hypercalls for
sPAPR's TCE (Translation Control Entry) IOMMU mechanism. This is necessary
for all virtual IO devices which do DMA (i.e. nearly all of them).
Signed-off-by: Ben Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Now that we have implemented the PAPR "xics" virtualized interrupt
controller, we can add interrupts in PAPR VIO devices. This patch adds
interrupt support to the PAPR virtual tty/console device.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This patch adds infrastructure to support interrupts from PAPR virtual IO
devices. This includes correctly advertising those interrupts in the
device tree, and implementing the H_VIO_SIGNAL hypercall, used to
enable and disable individual device interrupts.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
PAPR defines an interrupt control architecture which is logically divided
into ICS (Interrupt Control Presentation, each unit is responsible for
presenting interrupts to a particular "interrupt server", i.e. CPU) and
ICS (Interrupt Control Source, each unit responsible for one or more
hardware interrupts as numbered globally across the system). All PAPR
virtual IO devices expect to deliver interrupts via this mechanism. In
Linux, this interrupt controller system is handled by the "xics" driver.
On pSeries systems, access to the interrupt controller is virtualized via
hypercalls and RTAS methods. However, the virtualized interface is very
similar to the underlying interrupt controller hardware, and similar PICs
exist un-virtualized in some other systems.
This patch implements both the ICP and ICS sides of the PAPR interrupt
controller. For now, only the hypercall virtualized interface is provided,
however it would be relatively straightforward to graft an emulated
register interface onto the underlying interrupt logic if we want to add
a machine with a hardware ICS/ICP system in the future.
There are some limitations in this implementation: it is assumed for now
that only one instance of the ICS exists, although a full xics system can
have several, each responsible for a different group of hardware irqs.
ICP/ICS can handle both level-sensitve (LSI) and message signalled (MSI)
interrupt inputs. For now, this implementation supports only MSI
interrupts, since that is used by PAPR virtual IO devices.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This patch adds several small utility hypercalls and RTAS methods to
the pSeries platform emulation. Specifically:
* 'display-character' rtas call
This just prints a character to the console, it's occasionally used
for early debug of the OS. The support includes a hack to make this
RTAS call respond on the normal token value present on real hardware,
since some early debugging tools just assume this value without
checking the device tree.
* 'get-time-of-day' rtas call
This one just takes the host real time, converts to the PAPR described
format and returns it to the guest.
* 'power-off' rtas call
This one shuts down the emulated system.
* H_DABR hypercall
On pSeries, the DABR debug register is usually a hypervisor resource
and virtualized through this hypercall. If the hypercall is not
present, Linux will under some circumstances attempt to manipulate the
DABR directly which will fail on this emulated machine.
This stub implementation is enough to stop that behaviour, although it
doesn't actually implement the requested DABR operations as yet.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
On pSeries machines, operating systems can instantiate "RTAS" (Run-Time
Abstraction Services), a runtime component of the firmware which implements
a number of low-level, infrequently used operations. On logical partitions
under a hypervisor, many of the RTAS functions require hypervisor
privilege. For simplicity, therefore, hypervisor systems typically
implement the in-partition RTAS as just a tiny wrapper around a hypercall
which actually implements the various RTAS functions.
This patch implements such a hypercall based RTAS for our emulated pSeries
machine. A tiny in-partition "firmware" calls a new hypercall, which
looks up available RTAS services in a table.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
On pSeries logical partitions, excepting the old POWER4-style full system
partitions, the guest does not have direct access to the hardware page
table. Instead, the pagetable exists in hypervisor memory, and the guest
must manipulate it with hypercalls.
However, our current pSeries emulation more closely resembles the old
style where the guest must set up and handle the pagetables itself. This
patch converts it to act like a modern partition.
This involves two things: first, the hash translation path is modified to
permit the has table to be stored externally to the emulated machine's
RAM. The pSeries machine init code configures the CPUs to use this mode.
Secondly, we emulate the PAPR hypercalls for manipulating the external
hashed page table.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This extends the "pseries" (PAPR) machine to include a virtual IO bus
supporting the PAPR defined hypercall based virtual IO mechanisms.
So far only one VIO device is provided, the vty / vterm, providing
a full console (polled only, for now).
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This patch adds a "pseries" machine to qemu. This aims to emulate a
logical partition on an IBM pSeries machine, compliant to the
"PowerPC Architecture Platform Requirements" (PAPR) document.
This initial version is quite limited, it implements a basic machine
and PAPR hypercall emulation. So far only one hypercall is present -
H_PUT_TERM_CHAR - so that a (write-only) console is available.
Multiple CPUs are permitted, with SMP entry handled kexec() style.
The machine so far more resembles an old POWER4 style "full system
partition" rather than a modern LPAR, in that the guest manages the
page tables directly, rather than via hypercalls.
The machine requires qemu to be configured with --enable-fdt. The
machine can (so far) only be booted with -kernel - i.e. no partition
firmware is provided.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This adds emulation support for the recent POWER7 cpu to qemu. It's far
from perfect - it's missing a number of POWER7 features so far, including
any support for VSX or decimal floating point instructions. However, it's
close enough to boot a kernel with the POWER7 PVR.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Traditionally, the "segments" used for the two-stage translation used on
powerpc MMUs were 256MB in size. This was the only option on all hash
page table based 32-bit powerpc cpus, and on the earlier 64-bit hash page
table based cpus. However, newer 64-bit cpus also permit 1TB segments
This patch adds support for 1TB segment translation to the qemu code.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Currently the path handling hash page table translation in get_segment()
has a mix of common and 32 or 64 bit specific code. However the
division is not done terribly well which results in a lot of messy code
flipping between common and divided paths.
This patch improves the organization, consolidating several divided paths
into one. This in turn allows simplification of some code in
get_segment(), removing a number of ugly interim variables.
This new factorization will also make it easier to add support for the 1T
segments added in newer CPUs.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Currently, get_segment() has a variable called hash. However it doesn't
(quite) get the hash value for the ppc hashed page table. Instead it
gets the hash shifted - effectively the offset of the hash bucket within
the hash page table.
As well, as being different to the normal use of plain "hash" in the
architecture documentation, this usage necessitates some awkward 32/64
dependent masks and shifts which clutter up the path in get_segment().
This patch alters the code to use raw hash values through get_segment()
including storing raw hashes instead of pte group offsets in the ctx
structure. This cleans up the path noticeably.
This does necessitate 32/64 dependent shifts when the hash values are
taken out of the ctx structure and used, but those paths already have
32/64 bit variants so this is less awkward than it was in get_segment().
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
On ppc machines with hash table MMUs, the special purpose register SDR1
contains both the base address of the encoded size (hashed) page tables.
At present, we interpret the SDR1 value within the address translation
path. But because the encodings of the size for 32-bit and 64-bit are
different this makes for a confusing branch on the MMU type with a bunch
of curly shifts and masks in the middle of the translate path.
This patch cleans things up by moving the interpretation on SDR1 into the
helper function handling the write to the register. This leaves a simple
pre-sanitized base address and mask for the hash table in the CPUState
structure which is easier to work with in the translation path.
This makes the translation path more readable. It addresses the FIXME
comment currently in the mtsdr1 helper, by validating the SDR1 value during
interpretation. Finally it opens the way for emulating a pSeries-style
partition where the hash table used for translation is not mapped into
the guests's RAM.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
The slb_lookup() function, used in the ppc translation path returns a
number of slb entry fields in reference parameters. However, only one
of the two callers of slb_lookup() actually wants this information.
This patch, therefore, makes slb_lookup() return a simple pointer to the
located SLB entry (or NULL), and the caller which needs the fields can
extract them itself.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
qemu already includes support for the popcntb instruction introduced
in POWER5 (although it doesn't actually allow you to choose POWER5).
However, the logic is slightly incorrect: it will generate results
truncated to 32-bits when the CPU is in 32-bit mode. This is not
normal for powerpc - generally arithmetic instructions on a 64-bit
powerpc cpu will generate full 64 bit results, it's just that only the
low 32 bits will be significant for condition codes.
This patch corrects this nit, which actually simplifies the code slightly.
In addition, this patch implements the popcntw and popcntd
instructions added in POWER7, in preparation for allowing POWER7 as an
emulated CPU.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
The PURR (Processor Utilization Resource Register) is a register found
on recent POWER CPUs. The guts of implementing it at least enough to
get by are already present in qemu, however some of the helper
functions needed to actually wire it up are missing.
This patch adds the necessary glue, so that the PURR can be wired up
when we implement newer POWER CPU targets which include it.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
For a 64-bit PowerPC target, qemu correctly implements translation
through the segment lookaside buffer. Likewise it supports the
slbmte instruction which is used to load entries into the SLB.
However, it does not emulate the slbmfee and slbmfev instructions
which read SLB entries back into registers. Because these are
only occasionally used in guests (mostly for debugging) we get
away with it.
However, given the recent SLB cleanups, it becomes quite easy to
implement these, and thereby allow, amongst other things, a guest
Linux to use xmon's command to dump the SLB.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
PowerPC and POWER chips since the POWER4 and 970 have a special
hypervisor mode, and a corresponding form of the system call
instruction which traps to the hypervisor.
qemu currently has stub implementations of hypervisor mode. That
is, the outline is there to allow qemu to run a PowerPC hypervisor
under emulation. There are a number of details missing so this
won't actually work at present, but the idea is there.
What there is no provision at all, is for qemu to instead emulate
the hypervisor itself. That is to have hypercalls trap into qemu
and their result be emulated from qemu, rather than running
hypervisor code within the emulated system.
Hypervisor hardware aware KVM implementations are in the works and
it would be useful for debugging and development to also allow
full emulation of the same para-virtualized guests as such a KVM.
Therefore, this patch adds a hook which will allow a machine to
set up emulation of hypervisor calls.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Currently qemu_devtree_setprop() expects the new property value to be
given as a uint32_t *. While property values consisting of u32s are
common, in general they can have any bytestring value.
Therefore, this patch alters the function to take a void * instead,
allowing callers to easily give anything as the property value.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
Currently the SLB information when emulating a PowerPC 970 is
storeed in a structure with the unhelpfully named fields 'tmp'
and 'tmp64'. While the layout in these fields does match the
description of the SLB in the architecture document, it is not
convenient either for looking up the SLB, or for emulating the
slbmte instruction.
This patch, therefore, reorganizes the SLB entry structure to be
divided in the the "ESID related" and "VSID related" fields as
they are divided in instructions accessing the SLB.
In addition to making the code smaller and more readable, this will
make it easier to implement for the 1TB segments used in more
recent PowerPC chips.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Instead of a for loop use a faster lookup table.
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
To be consistent with the new reference manual.
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
SLIRP -smb support wants to fork a process and forget about reaping it.
To please it, add a generic service to register a process id and let
QEMU reap it. In the future it could be enhanced to pass a status,
but this would be unused.
With this in place, the SIGCHLD signal handler would not stomp on pclose
anymore.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
vhost was passing a physical address to cpu_physical_memory_set_dirty,
which is wrong: we need to translate to ram address first.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Note: this lead to crashes during migration, so the patch
is needed on the stable branch too.
Reduce spurious packet drops on RX ring empty
by verifying that we have at least 1 buffer
ahead of the time.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Commit c81131db15
detects old guests by comparing virtio and
PCI status. It attempts to do this on load,
as well, but load_config callback in a binding
is invoked too early and so the virtio status
isn't set yet.
We could add yet another callback to the
binding, to invoke after load, but it
seems easier to reuse the existing vmstate
callback.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Alexander Graf <agraf@suse.de>
