The dh_alias redirect is intended to handle TCG types as distinguished
from C types. TCG does not distinguish signed int from unsigned int,
because they are the same size. However, we need to retain this
distinction for dh_typecode, lest we fail to extend abi types properly
for the host call parameters.
This bug was detected when running the 'arm' emulator on an s390
system. The s390 uses TCG_TARGET_EXTEND_ARGS which triggers code
in tcg_gen_callN to extend 32 bit values to 64 bits; the incorrect
sign data in the typemask for each argument caused the values to be
extended as unsigned values.
This simple program exhibits the problem:
static volatile int num = -9;
static volatile int den = -5;
int main(void)
{
int quo = num / den;
printf("num %d den %d quo %d\n", num, den, quo);
exit(0);
}
When run on the broken qemu, this results in:
num -9 den -5 quo 0
The correct result is:
num -9 den -5 quo 1
Fixes: 7319d83a73 ("tcg: Combine dh_is_64bit and dh_is_signed to dh_typecode")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/876
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reported-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Tested-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Tested-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Many files use "qemu/log.h" declarations but neglect to include
it (they inherit it via "exec/exec-all.h"). "exec/exec-all.h" is
a core component and shouldn't be used that way. Move the
"qemu/log.h" inclusion locally to each unit requiring it.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20220207082756.82600-10-f4bug@amsat.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
"exec/ramblock.h" requires "qemu/rcu.h" for the definition of
rcu_head, and "exec/ramlist.h" for the definition of RAMBlockNotifier.
Add them to avoid when when refactoring include/:
include/exec/ramblock.h:26:21: error: field has incomplete type 'struct rcu_head'
struct rcu_head rcu;
^
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220207082756.82600-6-f4bug@amsat.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
TARGET_ABI_FMT_lx isn't available for softmmu which causes confusion
when trying to print. As abi_ptr == target_ulong use its format string
instead.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Now we have no TCG trace events and no longer handle them in the code
we can remove the handling from the tracetool to generate them. vcpu
tracing is still available although the existing syscall event is an
exercise in redundancy (plugins and -strace can also get the
information).
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Cc: Luis Vilanova <vilanova@imperial.ac.uk>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20220204204335.1689602-21-alex.bennee@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Cc: Luis Vilanova <vilanova@imperial.ac.uk>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220204204335.1689602-20-alex.bennee@linaro.org>
"host" pages are related to the *host* not the *target*,
thus the qemu_host_page_size / qemu_host_page_mask variables
and the HOST_PAGE_ALIGN() / REAL_HOST_PAGE_ALIGN() macros
can be moved to "exec/cpu-common.h" which is target agnostic.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20220120000836.229419-1-f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
dma_memory_set() does a DMA barrier, set the address space with
a constant value. The constant value filling code is not specific
to DMA and can be used for AddressSpace. Extract it as a new
helper: address_space_set().
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[lv: rebase]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220115203725.3834712-2-laurent@vivier.eu>
Let's update the documentation, making it clearer what the semantics
of memory_region_is_mapped() actually are.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20211102164317.45658-4-david@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
memory_region_is_mapped() currently does not return "true" when a memory
region is mapped via an alias.
Assuming we have:
alias (A0) -> alias (A1) -> region (R0)
Mapping A0 would currently only make memory_region_is_mapped() succeed
on A0, but not on A1 and R0.
Let's fix that by adding a "mapped_via_alias" counter to memory regions and
updating it accordingly when an alias gets (un)mapped.
I am not aware of actual issues, this is rather a cleanup to make it
consistent.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20211102164317.45658-3-david@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Adding defines to handle signed 64-bit and unsigned 128-bit quantities in
memory accesses.
Signed-off-by: Frédéric Pétrot <frederic.petrot@univ-grenoble-alpes.fr>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220106210108.138226-3-frederic.petrot@univ-grenoble-alpes.fr
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Renaming defines for quad in their various forms so that their signedness is
now explicit.
Done using git grep as suggested by Philippe, with a bit of hand edition to
keep assignments aligned.
Signed-off-by: Frédéric Pétrot <frederic.petrot@univ-grenoble-alpes.fr>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220106210108.138226-2-frederic.petrot@univ-grenoble-alpes.fr
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
"if (tcg_enabled())" allows elision of the code inside it; we only need
the prototype to exist, so that the code compile even for the --disable-tcg
case.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Here we introduce a new compiler flag to disable the checking of exit
request (icount_decr.u32). This is useful when we want to ensure the
next block cannot be preempted by an asynchronous event.
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211129140932.4115115-2-alex.bennee@linaro.org>
Currently we make the assumption that the guest frontend loads all
op code bytes sequentially. This mostly holds up for regular fixed
encodings but some architectures like s390x like to re-read the
instruction which causes weirdness to occur. Rather than changing the
frontends make the plugin API a little more ergonomic and able to
handle the re-read case.
Stuff will still get strange if we read ahead of the opcode but so far
no front ends have done that and this patch asserts the case so we can
catch it early if they do.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211026102234.3961636-21-alex.bennee@linaro.org>
to linux-user/host/arch/host-signal.h
- Replace TCGCPUOps.tlb_fill with TCGCPUOps.record_sigsegv for user-only
- Add TCGCPUOps.record_sigbus for user-only
- Remove a lot of target-specific cpu_loop handling for signals,
now accomplished with generic code.
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Merge remote-tracking branch 'remotes/rth/tags/pull-tcg-20211102' into staging
- Split out host signal handing from accel/tcg/user-exec.c
to linux-user/host/arch/host-signal.h
- Replace TCGCPUOps.tlb_fill with TCGCPUOps.record_sigsegv for user-only
- Add TCGCPUOps.record_sigbus for user-only
- Remove a lot of target-specific cpu_loop handling for signals,
now accomplished with generic code.
# gpg: Signature made Tue 02 Nov 2021 07:06:14 AM EDT
# gpg: using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg: issuer "richard.henderson@linaro.org"
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>" [ultimate]
* remotes/rth/tags/pull-tcg-20211102: (60 commits)
linux-user: Handle BUS_ADRALN in host_signal_handler
tcg: Add helper_unaligned_{ld,st} for user-only sigbus
accel/tcg: Report unaligned load/store for user-only
accel/tcg: Report unaligned atomics for user-only
target/sparc: Set fault address in sparc_cpu_do_unaligned_access
target/sparc: Split out build_sfsr
target/sparc: Remove DEBUG_UNALIGNED
target/sh4: Set fault address in superh_cpu_do_unaligned_access
target/s390x: Implement s390x_cpu_record_sigbus
linux-user/ppc: Remove POWERPC_EXCP_ALIGN handling
target/ppc: Restrict ppc_cpu_do_unaligned_access to sysemu
target/ppc: Set fault address in ppc_cpu_do_unaligned_access
target/ppc: Move SPR_DSISR setting to powerpc_excp
target/microblaze: Do not set MO_ALIGN for user-only
linux-user/hppa: Remove EXCP_UNALIGN handling
target/arm: Implement arm_cpu_record_sigbus
target/alpha: Implement alpha_cpu_record_sigbus
linux-user: Add cpu_loop_exit_sigbus
hw/core: Add TCGCPUOps.record_sigbus
accel/tcg: Restrict TCGCPUOps::tlb_fill() to sysemu
...
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This is a counterpart to the HMP "info opcount" command. It is being
added with an "x-" prefix because this QMP command is intended as an
ad hoc debugging tool and will thus not be modelled in QAPI as fully
structured data, nor will it have long term guaranteed stability.
The existing HMP command is rewritten to call the QMP command.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This is a counterpart to the HMP "info jit" command. It is being
added with an "x-" prefix because this QMP command is intended as an
ad hoc debugging tool and will thus not be modelled in QAPI as fully
structured data, nor will it have long term guaranteed stability.
The existing HMP command is rewritten to call the QMP command.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This is a counterpart to the HMP "info ramblock" command. It is being
added with an "x-" prefix because this QMP command is intended as an
adhoc debugging tool and will thus not be modelled in QAPI as fully
structured data, nor will it have long term guaranteed stability.
The existing HMP command is rewritten to call the QMP command.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This is a new interface to be provided by the os emulator for
raising SIGBUS on fault. Use the new record_sigbus target hook.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This is a new interface to be provided by the os emulator for
raising SIGSEGV on fault. Use the new record_sigsegv target hook.
Reviewed by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Now that all of the linux-user hosts have been converted
to host-signal.h, drop the compatibility code.
Reviewed by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
introduce global var total_dirty_pages to stat dirty pages
along with memory_global_dirty_log_sync.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Introduce replay_discarded callback similar to our existing
replay_populated callback, to be used my migration code to never migrate
discarded memory.
Acked-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
since dirty ring has been introduced, there are two methods
to track dirty pages of vm. it seems that "logging" has
a hint on the method, so rename the global_dirty_log to
global_dirty_tracking would make description more accurate.
dirty rate measurement may start or stop dirty tracking during
calculation. this conflict with migration because stop dirty
tracking make migration leave dirty pages out then that'll be
a problem.
make global_dirty_tracking a bitmask can let both migration and
dirty rate measurement work fine. introduce GLOBAL_DIRTY_MIGRATION
and GLOBAL_DIRTY_DIRTY_RATE to distinguish what current dirty
tracking aims for, migration or dirty rate.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Message-Id: <9c9388657cfa0301bd2c1cfa36e7cf6da4aeca19.1624040308.git.huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This is the major portion of handle_cpu_signal which is specific
to tcg, handling the page protections for the translations.
Most of the rest will migrate to linux-user/ shortly.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
v2: Pass guest address to handle_sigsegv_accerr_write.
Split out a function to adjust the raw signal pc into a
value that could be passed to cpu_restore_state.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
v2: Adjust pc in place; return MMUAccessType.
The previous placement in tcg/tcg.h was not logical.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
These functions are much closer to the softmmu helper
functions, in that they take the complete MemOpIdx,
and from that they may enforce required alignment.
The previous cpu_ldst.h functions did not have alignment info,
and so did not enforce it. Retain this by adding MO_UNALN to
the MemOp that we create in calling the new functions.
Note that we are not yet enforcing alignment for user-only,
but we now have the information with which to do so.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Move this code from tcg/tcg.h to its own header.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We have lacked expressive support for memory sizes larger
than 64-bits for a while. Fixing that requires adjustment
to several points where we used this for array indexing,
and two places that develop -Wswitch warnings after the change.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Provide a name field for all the memory listeners. It can be used to identify
which memory listener is which.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210817013553.30584-2-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a new RAMBlock flag to denote "protected" memory, i.e. memory that
looks and acts like RAM but is inaccessible via normal mechanisms,
including DMA. Use the flag to skip protected memory regions when
mapping RAM for DMA in VFIO.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There is nothing target specific about this. The implementation
is host specific, but the declaration is 100% common.
Reviewed-By: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
translate_insn() implementations fetch instruction bytes piecemeal,
which can cause qemu-user to generate inconsistent translations if
another thread modifies them concurrently [1].
Fix by making pages containing translated instruction non-writable
right before loading instruction bytes from them.
[1] https://lists.nongnu.org/archive/html/qemu-devel/2021-08/msg00644.html
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20210805204835.158918-1-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
[rth: Split out of a larger patch.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Now we have removed all the uses of gen_io_end() from target frontends,
the only callsite is inside gen_tb_start(). Inline the code there,
and remove the reference to it from the documentation.
While we are inlining the code, switch it to use tcg_constant_i32()
so we don't have to manually create and destroy a TCG temporary.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210724134902.7785-3-peter.maydell@linaro.org>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Set CF_SINGLE_STEP when single-stepping is enabled.
This avoids the need to flush all tb's when turning
single-stepping on or off.
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The hook is now unused, with breakpoints checked outside translation.
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Move the -d nochain check to bits on tb->cflags.
These will be used for more than -d nochain shortly.
Set bits during curr_cflags, test them in translator_use_goto_tb,
assert we're not doing anything odd in tcg_gen_goto_tb. The test
in tcg_gen_exit_tb is redundant with the assert for goto_tb_issue_mask.
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20210717221851.2124573-4-richard.henderson@linaro.org>
We will shortly have more than a simple member read here,
with stuff not necessarily exposed to exec/exec-all.h.
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210717221851.2124573-3-richard.henderson@linaro.org>
The space reserved for CF_COUNT_MASK was overly large.
Reduce to free up cflags bits and eliminate an extra test.
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20210717221851.2124573-2-richard.henderson@linaro.org>
Add a generic version of the common use_goto_tb test.
Various targets avoid the page crossing test for CONFIG_USER_ONLY,
but that is wrong: mmap and mprotect can change page permissions.
Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We want to separate the two cases whereby we discard ram
- uncoordinated: e.g., virito-balloon
- coordinated: e.g., virtio-mem coordinated via the RamDiscardManager
Reviewed-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Auger Eric <eric.auger@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: teawater <teawaterz@linux.alibaba.com>
Cc: Marek Kedzierski <mkedzier@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210413095531.25603-12-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
In case one wants to create a permanent copy of a MemoryRegionSections,
one needs access to flatview_ref()/flatview_unref(). Instead of exposing
these, let's just add helpers to copy/free a MemoryRegionSection and
properly adjust references.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Auger Eric <eric.auger@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: teawater <teawaterz@linux.alibaba.com>
Cc: Marek Kedzierski <mkedzier@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210413095531.25603-3-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
We have some special RAM memory regions (managed by virtio-mem), whereby
the guest agreed to only use selected memory ranges. "unused" parts are
discarded so they won't consume memory - to logically unplug these memory
ranges. Before the VM is allowed to use such logically unplugged memory
again, coordination with the hypervisor is required.
This results in "sparse" mmaps/RAMBlocks/memory regions, whereby only
coordinated parts are valid to be used/accessed by the VM.
In most cases, we don't care about that - e.g., in KVM, we simply have a
single KVM memory slot. However, in case of vfio, registering the
whole region with the kernel results in all pages getting pinned, and
therefore an unexpected high memory consumption - discarding of RAM in
that context is broken.
Let's introduce a way to coordinate discarding/populating memory within a
RAM memory region with such special consumers of RAM memory regions: they
can register as listeners and get updates on memory getting discarded and
populated. Using this machinery, vfio will be able to map only the
currently populated parts, resulting in discarded parts not getting pinned
and not consuming memory.
A RamDiscardManager has to be set for a memory region before it is getting
mapped, and cannot change while the memory region is mapped.
Note: At some point, we might want to let RAMBlock users (esp. vfio used
for nvme://) consume this interface as well. We'll need RAMBlock notifier
calls when a RAMBlock is getting mapped/unmapped (via the corresponding
memory region), so we can properly register a listener there as well.
Reviewed-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Auger Eric <eric.auger@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: teawater <teawaterz@linux.alibaba.com>
Cc: Marek Kedzierski <mkedzier@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210413095531.25603-2-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
We will shortly be interested in distinguishing pointers
from integers in the helper's declaration, as well as a
true void return. We currently have two parallel 1 bit
fields; merge them and expand to a 3 bit field.
Our current maximum is 7 helper arguments, plus the return
makes 8 * 3 = 24 bits used within the uint32_t typemask.
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Let's introduce RAM_NORESERVE, allowing mmap'ing with MAP_NORESERVE. The
new flag has the following semantics:
"
RAM is mmap-ed with MAP_NORESERVE. When set, reserving swap space (or huge
pages if applicable) is skipped: will bail out if not supported. When not
set, the OS will do the reservation, if supported for the memory type.
"
Allow passing it into:
- memory_region_init_ram_nomigrate()
- memory_region_init_resizeable_ram()
- memory_region_init_ram_from_file()
... and teach qemu_ram_mmap() and qemu_anon_ram_alloc() about the flag.
Bail out if the flag is not supported, which is the case right now for
both, POSIX and win32. We will add Linux support next and allow specifying
RAM_NORESERVE via memory backends.
The target use case is virtio-mem, which dynamically exposes memory
inside a large, sparse memory area to the VM.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com> for memory backend and machine core
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210510114328.21835-9-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
