Especially for guests with large numbers of tlbs, like ARM or PPC,
we may well not use all of them in between flush operations.
Remember which tlbs have been used since the last flush, and
avoid any useless flushing.
Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Our only statistic so far was "full" tlb flushes, where all mmu_idx
are flushed at the same time.
Now count "partial" tlb flushes where sets of mmu_idx are flushed,
but the set is not maximal. Account one per mmu_idx flushed, as
that is the unit of work performed.
We don't actually count elided flushes yet, but go ahead and change
the interface presented to the monitor all at once.
Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The rest of the tlb victim cache is per-tlb,
the next use index should be as well.
Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The set of large pages in the kernel is probably not the same
as the set of large pages in the application. Forcing one
range to cover both will flush more often than necessary.
This allows tlb_flush_page_async_work to flush just the one
mmu_idx implicated, which in turn allows us to remove
tlb_check_page_and_flush_by_mmuidx_async_work.
Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Protect it with the tlb_lock instead of using atomics.
The move puts it in or near the same cacheline as the lock;
using the lock means we don't need a second atomic operation
in order to perform the update. Which makes it cheap to also
update pending_flush in tlb_flush_by_mmuidx_async_work.
Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This is the first of several moves to reduce the size of the
CPU_COMMON_TLB macro and improve some locality of refernce.
Tested-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
QEMU trivial patches collected between June and October 2018
(Thank you to Thomas Huth)
v2: fix 32bit build with updated patch (v3) from Philippe Mathieu-Daudé
built in a 32bit debian sid chroot
# gpg: Signature made Tue 30 Oct 2018 11:23:01 GMT
# gpg: using RSA key F30C38BD3F2FBE3C
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>"
# gpg: aka "Laurent Vivier <laurent@vivier.eu>"
# gpg: aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>"
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F 5173 F30C 38BD 3F2F BE3C
* remotes/vivier2/tags/qemu-trivial-for-3.1-pull-request:
milkymist-minimac2: Use qemu_log_mask(GUEST_ERROR) instead of error_report
ppc: move at24c to its own CONFIG_ symbol
hw/intc/gicv3: Remove useless parenthesis around DIV_ROUND_UP macro
hw/pci-host: Remove useless parenthesis around DIV_ROUND_UP macro
tests/bios-tables-test: Remove an useless cast
xen: Use the PCI_DEVICE macro
qobject: Catch another straggler for use of qdict_put_str()
configure: Support pkg-config for zlib
tests: Fix typos in comments and help message (found by codespell)
cpu.h: fix a typo in comment
linux-user: fix comment s/atomic_write/atomic_set/
qemu-iotests: make 218 executable
scripts/qemu.py: remove trailing quotes on docstring
scripts/decodetree.py: remove unused imports
docs/devel/testing.rst: add missing newlines after code block
qemu-iotests: fix filename containing checks
tests/tcg/README: fix location for lm32 tests
memory.h: fix typos in comments
vga_int: remove unused function protype
configs/alpha: Remove unused CONFIG_PARALLEL_ISA switch
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We should not load PVM's state directly into SVM, because there maybe some
errors happen when SVM is receving data, which will break SVM.
We need to ensure receving all data before load the state into SVM. We use
an extra memory to cache these data (PVM's ram). The ram cache in secondary side
is initially the same as SVM/PVM's memory. And in the process of checkpoint,
we cache the dirty pages of PVM into this ram cache firstly, so this ram cache
always the same as PVM's memory at every checkpoint, then we flush this cached ram
to SVM after we receive all PVM's state.
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Zhang Chen <zhangckid@gmail.com>
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Currently we rely on atomic operations for cross-CPU invalidations.
There are two cases that these atomics miss: cross-CPU invalidations
can race with either (1) vCPU threads flushing their TLB, which
happens via memset, or (2) vCPUs calling tlb_reset_dirty on their TLB,
which updates .addr_write with a regular store. This results in
undefined behaviour, since we're mixing regular and atomic ops
on concurrent accesses.
Fix it by using tlb_lock, a per-vCPU lock. All updaters of tlb_table
and the corresponding victim cache now hold the lock.
The readers that do not hold tlb_lock must use atomic reads when
reading .addr_write, since this field can be updated by other threads;
the conversion to atomic reads is done in the next patch.
Note that an alternative fix would be to expand the use of atomic ops.
However, in the case of TLB flushes this would have a huge performance
impact, since (1) TLB flushes can happen very frequently and (2) we
currently use a full memory barrier to flush each TLB entry, and a TLB
has many entries. Instead, acquiring the lock is barely slower than a
full memory barrier since it is uncontended, and with a single lock
acquisition we can flush the entire TLB.
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20181009174557.16125-6-cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Before this change, memory-backend-file object is valid for Linux hosts
only because hostmem-file.c is compiled only on Linux hosts.
However, other POSIX-based hosts (such as macOS) can support
memory-backend-file object in the same way as on Linux hosts.
This patch makes hostmem-file.c and related functions to be compiled on
all POSIX-based hosts to make available memory-backend-file on them.
Signed-off-by: Hikaru Nishida <hikarupsp@gmail.com>
Message-Id: <20180924123205.29651-1-hikarupsp@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There is no known available OS for ppc around anymore that uses page
sizes below 4k, so it does not make much sense that we keep wasting
our time on building and testing the ppcemb-softmmu target. It has
been deprecated since two releases, and nobody complained, so let's
remove this now.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
