This patch adds the T-Head C906 to the list of known CPUs.
Selecting this CPUs will automatically enable the available
ISA extensions of the CPUs (incl. vendor extensions).
Co-developed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-Id: <20230131202013.2541053-13-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
There are no differences for floating point instructions in priv version 1.11
and 1.12. There is also no dependency for Zfh to priv version 1.12.
Therefore allow Zfh to be enabled for priv version 1.11.
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-Id: <20230131202013.2541053-12-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This patch adds support for the T-Head FMemIdx instructions.
The patch uses the T-Head specific decoder and translation.
Co-developed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-Id: <20230131202013.2541053-11-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This patch adds support for the T-Head MemIdx instructions.
The patch uses the T-Head specific decoder and translation.
Co-developed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-Id: <20230131202013.2541053-10-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This patch adds support for the T-Head MemPair instructions.
The patch uses the T-Head specific decoder and translation.
Co-developed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-Id: <20230131202013.2541053-9-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This patch adds support for the T-Head MAC instructions.
The patch uses the T-Head specific decoder and translation.
Co-developed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-Id: <20230131202013.2541053-8-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This patch adds support for the XTheadCondMov ISA extension.
The patch uses the T-Head specific decoder and translation.
Co-developed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-Id: <20230131202013.2541053-7-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This patch adds support for the XTheadBs ISA extension.
The patch uses the T-Head specific decoder and translation.
Co-developed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Co-developed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-Id: <20230131202013.2541053-6-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This patch adds support for the XTheadBb ISA extension.
The patch uses the T-Head specific decoder and translation.
Co-developed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Co-developed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-Id: <20230131202013.2541053-5-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This patch adds support for the XTheadBa ISA extension.
The patch uses the T-Head specific decoder and translation.
Co-developed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Co-developed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-Id: <20230131202013.2541053-4-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This patch adds support for the XTheadSync ISA extension.
The patch uses the T-Head specific decoder and translation.
The implementation introduces a helper to execute synchronization tasks:
helper_tlb_flush_all() performs a synchronized TLB flush on all CPUs.
Co-developed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Message-Id: <20230131202013.2541053-3-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This patch adds support for the XTheadCmo ISA extension.
To avoid interfering with standard extensions, decoder and translation
are in its own xthead* specific files.
Future patches should be able to easily add additional T-Head extension.
The implementation does not have much functionality (besides accepting
the instructions and not qualifying them as illegal instructions if
the hart executes in the required privilege level for the instruction),
as QEMU does not model CPU caches and instructions are documented
to not raise any exceptions.
Co-developed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230131202013.2541053-2-christoph.muellner@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
As it is now, riscv_compute_fdt_addr() is receiving a dram_base, a
mem_size (which is defaulted to MachineState::ram_size in all boards)
and the FDT pointer. And it makes a very important assumption: the DRAM
interval dram_base + mem_size is contiguous. This is indeed the case for
most boards that use a FDT.
The Icicle Kit board works with 2 distinct RAM banks that are separated
by a gap. We have a lower bank with 1GiB size, a gap follows, then at
64GiB the high memory starts. MachineClass::default_ram_size for this
board is set to 1.5Gb, and machine_init() is enforcing it as minimal RAM
size, meaning that there we'll always have at least 512 MiB in the Hi
RAM area.
Using riscv_compute_fdt_addr() in this board is weird because not only
the board has sparse RAM, and it's calling it using the base address of
the Lo RAM area, but it's also using a mem_size that we have guarantees
that it will go up to the Hi RAM. All the function assumptions doesn't
work for this board.
In fact, what makes the function works at all in this case is a
coincidence. Commit 1a475d39ef introduced a 3GB boundary for the FDT,
down from 4Gb, that is enforced if dram_base is lower than 3072 MiB. For
the Icicle Kit board, memmap[MICROCHIP_PFSOC_DRAM_LO].base is 0x80000000
(2 Gb) and it has a 1Gb size, so it will fall in the conditions to put
the FDT under a 3Gb address, which happens to be exactly at the end of
DRAM_LO. If the base address of the Lo area started later than 3Gb this
function would be unusable by the board. Changing any assumptions inside
riscv_compute_fdt_addr() can also break it by accident as well.
Let's change riscv_compute_fdt_addr() semantics to be appropriate to the
Icicle Kit board and for future boards that might have sparse RAM
topologies to worry about:
- relieve the condition that the dram_base + mem_size area is contiguous,
since this is already not the case today;
- receive an extra 'dram_size' size attribute that refers to a contiguous
RAM block that the board wants the FDT to reside on.
Together with 'mem_size' and 'fdt', which are now now being consumed by a
MachineState pointer, we're able to make clear assumptions based on the
DRAM block and total mem_size available to ensure that the FDT will be put
in a valid RAM address.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230201171212.1219375-4-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
A common trend in other archs is to calculate the fdt address, which is
usually straightforward, and then calling a function that loads the
fdt/dtb by using that address.
riscv_load_fdt() is doing a bit too much in comparison. It's calculating
the fdt address via an elaborated heuristic to put the FDT at the bottom
of DRAM, and "bottom of DRAM" will vary across boards and
configurations, then it's actually loading the fdt, and finally it's
returning the fdt address used to the caller.
Reduce the existing complexity of riscv_load_fdt() by splitting its code
into a new function, riscv_compute_fdt_addr(), that will take care of
all fdt address logic. riscv_load_fdt() can then be a simple function
that just loads a fdt at the given fdt address.
We're also taken the opportunity to clarify the intentions and
assumptions made by these functions. riscv_load_fdt() is now receiving a
hwaddr as fdt_addr because there is no restriction of having to load the
fdt in higher addresses that doesn't fit in an uint32_t.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-Id: <20230201171212.1219375-3-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
fdt_pack() can change the fdt size, meaning that fdt_totalsize() can
contain a now deprecated (bigger) value.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-Id: <20230201171212.1219375-2-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
According to privileged spec, if [sm]tval is written with a nonzero
value when a breakpoint exception occurs, then [sm]tval will contain
the faulting virtual address. Set tval to hit address when breakpoint
exception is triggered by hardware watchpoint.
Signed-off-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com>
Reviewed-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230131170955.752743-1-geomatsi@gmail.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Follow the QEMU convention of naming MachineState pointers as 'ms' by
renaming the instances where we're calling it 'mc'.
Suggested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-Id: <20230124212234.412630-4-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
We have a convention in other QEMU boards/archs to name MachineState
pointers as either 'machine' or 'ms'. MachineClass pointers are usually
called 'mc'.
The 'virt' RISC-V machine has a lot of instances where MachineState
pointers are named 'mc'. There is nothing wrong with that, but we gain
more compatibility with the rest of the QEMU code base, and easier
reviews, if we follow QEMU conventions.
Rename all 'mc' MachineState pointers to 'ms'. This is a very tedious
and mechanical patch that was produced by doing the following:
- find/replace all 'MachineState *mc' to 'MachineState *ms';
- find/replace all 'mc->fdt' to 'ms->fdt';
- find/replace all 'mc->smp.cpus' to 'ms->smp.cpus';
- replace any remaining occurrences of 'mc' that the compiler complained
about.
Suggested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-Id: <20230124212234.412630-3-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
riscv_socket_count() returns either ms->numa_state->num_nodes or 1
depending on NUMA support. In any case the value can be retrieved only
once and used in the rest of the function.
This will also alleviate the rename we're going to do next by reducing
the instances of MachineState 'mc' inside hw/riscv/virt.c.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-Id: <20230124212234.412630-2-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
We should call decode_save_opc() for all relevant instructions which
can potentially generate a virtual instruction fault or a guest page
fault because generating transformed instruction upon guest page fault
expects opcode to be available. Without this, hypervisor will see
transformed instruction as zero in htinst CSR for guest MMIO emulation
which makes MMIO emulation in hypervisor slow and also breaks nested
virtualization.
Fixes: a9814e3e08 ("target/riscv: Minimize the calls to decode_save_opc")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230120125950.2246378-5-apatel@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The time CSR will wrap-around immediately after reaching UINT64_MAX
so we don't need to re-start QEMU timer when timecmp == UINT64_MAX
in riscv_timer_write_timecmp().
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230120125950.2246378-4-apatel@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Instead of clearing mask in riscv_cpu_update_mip() for VSTIP, we
should call riscv_cpu_update_mip() with mask == 0 from timer_helper.c
for VSTIP.
Fixes: 3ec0fe18a3 ("target/riscv: Add vstimecmp suppor")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230120125950.2246378-3-apatel@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The htimedelta[h] CSR has impact on the VS timer comparison so we
should call riscv_timer_write_timecmp() whenever htimedelta changes.
Fixes: 3ec0fe18a3 ("target/riscv: Add vstimecmp suppor")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230120125950.2246378-2-apatel@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
If the CSRs and CSR instructions are disabled because the Zicsr
extension isn't enabled then we want to make sure we don't run any CSR
instructions in the boot ROM.
This patches removes the CSR instructions from the reset-vec if the
extension isn't enabled. We replace the instruction with a NOP instead.
Note that we don't do this for the SiFive U machine, as we are modelling
the hardware in that case.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1447
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-Id: <20230123035754.75553-1-alistair.francis@opensource.wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Updates the opentitan IRQs to match the latest supported commit of
Opentitan from TockOS.
OPENTITAN_SUPPORTED_SHA := 565e4af39760a123c59a184aa2f5812a961fde47
Memory layout as per [1]
[1] 565e4af397/hw/top_earlgrey/sw/autogen/top_earlgrey_memory.h
Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230123063619.222459-1-wilfred.mallawa@opensource.wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The decoding of the following instructions from Zb[abcs] currently
contains decoding/printing errors:
* xnor,orn,andn: the rs2 operand is not being printed
* slli.uw: decodes and prints the immediate shift-amount as a
register (e.g. 'shift-by-2' becomes 'sp') instead of
interpreting this as an immediate
This commit updates the instruction descriptions to use the
appropriate decoding/printing formats.
Signed-off-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230120151551.1022761-1-philipp.tomsich@vrull.eu>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
To support query migration thread infomation, save and delete
thread(live_migration and multifdsend) information at thread
creation and finish.
Signed-off-by: Jiang Jiacheng <jiangjiacheng@huawei.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Introduce interface query-migrationthreads. The interface is used
to query information about migration threads and returns with
migration thread's name and its id.
Introduce threadinfo.c to manage threads with migration.
Signed-off-by: Jiang Jiacheng <jiangjiacheng@huawei.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Make IO channel flush call after the inflight request has been drained
in multifd thread, or else we may missed to flush the inflight request.
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
In multifd_queue_page() MultiFDPages_t.block is checked twice.
Between the two checks, MultiFDPages_t.block may be reset to NULL
by multifd thread. This lead to the 2nd check always true then a
redundant page submitted to multifd thread again.
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Current logic assumes that channel connections on the destination side are
always established in the same order as the source and the first one will
always be the main channel followed by the multifid or post-copy
preemption channel. This may not be always true, as even if a channel has a
connection established on the source side it can be in the pending state on
the destination side and a newer connection can be established first.
Basically causing out of order mapping of channels on the destination side.
Currently, all channels except post-copy preempt send a magic number, this
patch uses that magic number to decide the type of channel. This logic is
applicable only for precopy(multifd) live migration, as mentioned, the
post-copy preempt channel does not send any magic number. Also, tls live
migrations already does tls handshake before creating other channels, so
this issue is not possible with tls, hence this logic is avoided for tls
live migrations. This patch uses read peek to check the magic number of
channels so that current data/control stream management remains
un-effected.
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Suggested-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: manish.mishra <manish.mishra@nutanix.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
MSG_PEEK peeks at the channel, The data is treated as unread and
the next read shall still return this data. This support is
currently added only for socket class. Extra parameter 'flags'
is added to io_readv calls to pass extra read flags like MSG_PEEK.
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Suggested-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: manish.mishra <manish.mishra@nutanix.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
The value of "Sample Pages" is confusing in mode other than page-sampling.
See below:
(qemu) calc_dirty_rate -b 10 520
(qemu) info dirty_rate
Status: measuring
Start Time: 11646834 (ms)
Sample Pages: 520 (per GB)
Period: 10 (sec)
Mode: dirty-bitmap
Dirty rate: (not ready)
(qemu) info dirty_rate
Status: measured
Start Time: 11646834 (ms)
Sample Pages: 0 (per GB)
Period: 10 (sec)
Mode: dirty-bitmap
Dirty rate: 2 (MB/s)
While it's totally useless in dirty-ring and dirty-bitmap mode, fix to
show it only in page-sampling mode.
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Perform a check on vmsd structures during test runs in the hope
of catching any missing terminators and other simple screwups.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
We fairly regularly forget VMSTATE_END_OF_LIST markers off descriptions;
given that the current check is only for ->name being NULL, sometimes
we get unlucky and the code apparently works and no one spots the error.
Explicitly add a flag, VMS_END that should be set, and assert it is
set during the traversal.
Note: This can't go in until we update the copy of vmstate.h in slirp.
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
upon errors. As the documentation in include/io/channel.h states, only
-1 and QIO_CHANNEL_ERR_BLOCK should be returned upon error. Other
values have the potential to confuse the call sites.
error_setg is used rather than error_setg_errno, because there are
certain code paths where -1 (as a non-errno) is propagated up (e.g.
starting from qemu_rdma_block_for_wrid or qemu_rdma_post_recv_control)
all the way to qio_channel_rdma_{readv,writev}.
Similar to a216ec85b7 ("migration/channel-block: fix return value for
qio_channel_block_{readv,writev}").
Suggested-by: Zhang Chen <chen.zhang@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
The downtime should be displayed during postcopy phase because the
switchover phase is done. OTOH it's weird to show "expected downtime"
which can confuse what does that mean if the switchover has already
happened anyway.
This is a slight ABI change on QMP, but I assume it shouldn't affect
anyone.
Reviewed-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Ordinary memory preallocation runs when QEMU starts up and creates the
memory backends, before processing the incoming migration stream. With
virtio-mem, we don't know which memory blocks to preallocate before
migration started. Now that we migrate the virtio-mem bitmap early, before
migrating any RAM content, we can safely preallocate memory for all plugged
memory blocks before migrating any RAM content.
This is especially relevant for the following cases:
(1) User errors
With hugetlb/files, if we don't have sufficient backend memory available on
the migration destination, we'll crash QEMU (SIGBUS) during RAM migration
when running out of backend memory. Preallocating memory before actual
RAM migration allows for failing gracefully and informing the user about
the setup problem.
(2) Excluded memory ranges during migration
For example, virtio-balloon free page hinting will exclude some pages
from getting migrated. In that case, we won't crash during RAM
migration, but later, when running the VM on the destination, which is
bad.
To fix this for new QEMU machines that migrate the bitmap early,
preallocate the memory early, before any RAM migration. Warn with old
QEMU machines.
Getting postcopy right is a bit tricky, but we essentially now implement
the same (problematic) preallocation logic as ordinary preallocation:
preallocate memory early and discard it again before precopy starts. During
ordinary preallocation, discarding of RAM happens when postcopy is advised.
As the state (bitmap) is loaded after postcopy was advised but before
postcopy starts listening, we have to discard memory we preallocated
immediately again ourselves.
Note that nothing (not even hugetlb reservations) guarantees for postcopy
that backend memory (especially, hugetlb pages) are still free after they
were freed ones while discarding RAM. Still, allocating that memory at
least once helps catching some basic setup problems.
Before this change, trying to restore a VM when insufficient hugetlb
pages are around results in the process crashing to to a "Bus error"
(SIGBUS). With this change, QEMU fails gracefully:
qemu-system-x86_64: qemu_prealloc_mem: preallocating memory failed: Bad address
qemu-system-x86_64: error while loading state for instance 0x0 of device '0000:00:03.0/virtio-mem-device-early'
qemu-system-x86_64: load of migration failed: Cannot allocate memory
And we can even introspect the early migration data, including the
bitmap:
$ ./scripts/analyze-migration.py -f STATEFILE
{
"ram (2)": {
"section sizes": {
"0000:00:03.0/mem0": "0x0000000780000000",
"0000:00:04.0/mem1": "0x0000000780000000",
"pc.ram": "0x0000000100000000",
"/rom@etc/acpi/tables": "0x0000000000020000",
"pc.bios": "0x0000000000040000",
"0000:00:02.0/e1000.rom": "0x0000000000040000",
"pc.rom": "0x0000000000020000",
"/rom@etc/table-loader": "0x0000000000001000",
"/rom@etc/acpi/rsdp": "0x0000000000001000"
}
},
"0000:00:03.0/virtio-mem-device-early (51)": {
"tmp": "00 00 00 01 40 00 00 00 00 00 00 07 80 00 00 00 00 00 00 00 00 20 00 00 00 00 00 00",
"size": "0x0000000040000000",
"bitmap": "ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [...]
},
"0000:00:04.0/virtio-mem-device-early (53)": {
"tmp": "00 00 00 08 c0 00 00 00 00 00 00 07 80 00 00 00 00 00 00 00 00 20 00 00 00 00 00 00",
"size": "0x00000001fa400000",
"bitmap": "ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [...]
},
[...]
Reported-by: Jing Qi <jinqi@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>S
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
The bitmap and the size are immutable while migration is active: see
virtio_mem_is_busy(). We can migrate this information early, before
migrating any actual RAM content. Further, all information we need for
sanity checks is immutable as well.
Having this information in place early will, for example, allow for
properly preallocating memory before touching these memory locations
during RAM migration: this way, we can make sure that all memory was
actually preallocated and that any user errors (e.g., insufficient
hugetlb pages) can be handled gracefully.
In contrast, usable_region_size and requested_size can theoretically
still be modified on the source while the VM is running. Keep migrating
these properties the usual, late, way.
Use a new device property to keep behavior of compat machines
unmodified.
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>S
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
"prealloc=on" for the memory backend does not work as expected, as
virtio-mem will simply discard all preallocated memory immediately again.
In the best case, it's an expensive NOP. In the worst case, it's an
unexpected allocation error.
Instead, "prealloc=on" should be specified for the virtio-mem device only,
such that virtio-mem will try preallocating memory before plugging
memory dynamically to the guest. Fail if such a memory backend is
provided.
Tested-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>S
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Let's factor out this check, to be used in virtio-mem context next.
While at it, fix a spelling error in a related comment.
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>S
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
We'll make use of both next in the context of virtio-mem.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>S
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
For virtio-mem, we want to have the plugged/unplugged state of memory
blocks available before migrating any actual RAM content, and perform
sanity checks before touching anything on the destination. This
information is immutable on the migration source while migration is active,
We want to use this information for proper preallocation support with
migration: currently, we don't preallocate memory on the migration target,
and especially with hugetlb, we can easily run out of hugetlb pages during
RAM migration and will crash (SIGBUS) instead of catching this gracefully
via preallocation.
Migrating device state via a VMSD before we start iterating is currently
impossible: the only approach that would be possible is avoiding a VMSD
and migrating state manually during save_setup(), to be restored during
load_state().
Let's allow for migrating device state via a VMSD early, during the
setup phase in qemu_savevm_state_setup(). To keep it simple, we
indicate applicable VMSD's using an "early_setup" flag.
Note that only very selected devices (i.e., ones seriously messing with
RAM setup) are supposed to make use of such early state migration.
While at it, also use a bool for the "unmigratable" member.
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>S
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
... and store it in the migration state. This is a preparation for
storing selected vmds's already in qemu_savevm_state_setup().
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Let's move more code into vmstate_save(), reducing code duplication and
preparing for reuse of vmstate_save() in qemu_savevm_state_setup(). We
have to move vmstate_save() to make the compiler happy.
We'll now also trace from qemu_save_device_state(), triggering the same
tracepoints as previously called from
qemu_savevm_state_complete_precopy_non_iterable() only. Note that
qemu_save_device_state() ignores iterable device state, such as RAM,
and consequently doesn't trigger some other trace points (e.g.,
trace_savevm_state_setup()).
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
ram_block_populate_read() already optimizes for RamDiscardManager.
However, ram_write_tracking_start() will still try protecting discarded
memory ranges.
Let's optimize, because discarded ranges don't map any pages and
(1) For anonymous memory, trying to protect using uffd-wp without a mapped
page is ignored by the kernel and consequently a NOP.
(2) For shared/file-backed memory, we will fill present page tables in the
range with PTE markers. However, we will even allocate page tables
just to fill them with unnecessary PTE markers and effectively
waste memory.
So let's exclude these ranges, just like ram_block_populate_read()
already does.
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
ram_mig_ram_block_resized() will abort migration (including background
snapshots) when resizing a RAMBlock. ram_block_populate_read() will only
populate RAM up to used_length, so at least for anonymous memory
protecting everything between used_length and max_length won't
actually be protected and is just a NOP.
So let's only protect everything up to used_length.
Note: it still makes sense to register uffd-wp for max_length, such
that RAM_UF_WRITEPROTECT is independent of a changing used_length.
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
When unregistering uffd-wp, older kernels before commit f369b07c86143
("mm/uffd:reset write protection when unregister with wp-mode") won't
clear the uffd-wp PTE bit. When re-registering uffd-wp, the previous
uffd-wp PTE bits would trigger again. With above commit, the kernel will
clear the uffd-wp PTE bits when unregistering itself.
Consequently, we'll clear the uffd-wp PTE bits now twice -- whereby we
don't care about clearing them at all: a new background snapshot will
re-register uffd-wp and re-protect all memory either way.
So let's skip the manual clearing of uffd-wp. If ever relevant, we
could clear conditionally in uffd_unregister_memory() -- we just need a
way to figure out more recent kernels.
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
If something goes wrong during uffd_change_protection(), we would miss
to unregister uffd-wp and not release our reference. Fix it by
performing the uffd_change_protection(true) last.
Note that a uffd_change_protection(false) on the recovery path without a
prior uffd_change_protection(false) is fine.
Fixes: 278e2f551a ("migration: support UFFD write fault processing in ram_save_iterate()")
Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Unfortunately, commit f7b9dcfbcf broke populate_read_range(): the loop
end condition is very wrong, resulting in that function not populating the
full range. Lets' fix that.
Fixes: f7b9dcfbcf ("migration/ram: Factor out populating pages readable in ram_block_populate_pages()")
Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Christoph Müllner
Daniel Henrique Barboza
Sergey Matyukevich
Anup Patel
Alistair Francis
Wilfred Mallawa
Philipp Tomsich
Jiang Jiacheng
Zhenzhong Duan
manish.mishra
Dr. David Alan Gilbert
Fiona Ebner
Peter Xu
David Hildenbrand