When icount is enabled and we recompile an MMIO access we end up
double counting the instruction execution. To avoid this we introduce
the CF_MEMI cflag which only allows memory instrumentation for the
next TB (which won't yet have been counted). As this is part of the
hashed compile flags we will only execute the generated TB while
coming out of a cpu_io_recompile.
While we are at it delete the old TODO. We might as well keep the
translation handy as it's likely you will repeatedly hit it on each
MMIO access.
Reported-by: Aaron Lindsay <aaron@os.amperecomputing.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Aaron Lindsay <aaron@os.amperecomputing.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210213130325.14781-21-alex.bennee@linaro.org>
Use g2h_untagged in contexts that have no cpu, e.g. the binary
loaders that operate before the primary cpu is created. As a
colollary, target_mmap and friends must use untagged addresses,
since they are used by the loaders.
Use g2h_untagged on values returned from target_mmap, as the
kernel never applies a tag itself.
Use g2h_untagged on all pc values. The only current user of
tags, aarch64, removes tags from code addresses upon branch,
so "pc" is always untagged.
Use g2h with the cpu context on hand wherever possible.
Use g2h_untagged in lock_user, which will be updated soon.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210212184902.1251044-13-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This is the only use of guest_addr_valid that does not begin
with a guest address, but a host address being transformed to
a guest address.
We will shortly adjust guest_addr_valid to handle guest memory
tags, and the host address should not be subjected to that.
Move h2g_valid adjacent to the other h2g macros.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210212184902.1251044-10-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Record whether the backing page is anonymous, or if it has file
backing. This will allow us to get close to the Linux AArch64
ABI for MTE, which allows tag memory only on ram-backed VMAs.
The real ABI allows tag memory on files, when those files are
on ram-backed filesystems, such as tmpfs. We will not be able
to implement that in QEMU linux-user.
Thankfully, anonymous memory for malloc arenas is the primary
consumer of this feature, so this restricted version should
still be of use.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210212184902.1251044-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Migration pull 2021-02-08
v2
Dropped vmstate: Fix memory leak in vmstate_handle_alloc
Broke on Power
Added migration: only check page size match if RAM postcopy is enabled
# gpg: Signature made Mon 08 Feb 2021 11:28:14 GMT
# gpg: using RSA key 45F5C71B4A0CB7FB977A9FA90516331EBC5BFDE7
# gpg: Good signature from "Dr. David Alan Gilbert (RH2) <dgilbert@redhat.com>" [full]
# Primary key fingerprint: 45F5 C71B 4A0C B7FB 977A 9FA9 0516 331E BC5B FDE7
* remotes/dgilbert/tags/pull-migration-20210208a: (27 commits)
migration: only check page size match if RAM postcopy is enabled
migration: introduce snapshot-{save, load, delete} QMP commands
iotests: fix loading of common.config from tests/ subdir
iotests: add support for capturing and matching QMP events
migration: introduce a delete_snapshot wrapper
migration: wire up support for snapshot device selection
migration: control whether snapshots are ovewritten
block: rename and alter bdrv_all_find_snapshot semantics
block: allow specifying name of block device for vmstate storage
block: add ability to specify list of blockdevs during snapshot
migration: stop returning errno from load_snapshot()
migration: Make save_snapshot() return bool, not 0/-1
block: push error reporting into bdrv_all_*_snapshot functions
migration: Display the migration blockers
migration: Add blocker information
migration: Fix a few absurdly defective error messages
migration: Fix cache_init()'s "Failed to allocate" error messages
migration: Clean up signed vs. unsigned XBZRLE cache-size
migration: Fix migrate-set-parameters argument validation
migration: introduce 'userfaultfd-wrlat.py' script
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We passed an is_write flag to the fuzz_dma_read_cb function to
differentiate between the mapped DMA regions that need to be populated
with fuzzed data, and those that don't. We simply passed through the
address_space_map is_write parameter. The goal was to cut down on
unnecessarily populating mapped DMA regions, when they are not read
from.
Unfortunately, nothing precludes code from reading from regions mapped
with is_write=true. For example, see:
https://lists.gnu.org/archive/html/qemu-devel/2021-01/msg04729.html
This patch removes the is_write parameter to fuzz_dma_read_cb. As a
result, we will fill all mapped DMA regions with fuzzed data, ignoring
the specified transfer direction.
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Message-Id: <20210120060255.558535-1-alxndr@bu.edu>
In this particular implementation the same single migration
thread is responsible for both normal linear dirty page
migration and procesing UFFD page fault events.
Processing write faults includes reading UFFD file descriptor,
finding respective RAM block and saving faulting page to
the migration stream. After page has been saved, write protection
can be removed. Since asynchronous version of qemu_put_buffer()
is expected to be used to save pages, we also have to flush
migraion stream prior to un-protecting saved memory range.
Write protection is being removed for any previously protected
memory chunk that has hit the migration stream. That's valid
for pages from linear page scan along with write fault pages.
Signed-off-by: Andrey Gruzdev <andrey.gruzdev@virtuozzo.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20210129101407.103458-4-andrey.gruzdev@virtuozzo.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
fixup pagefault.address cast for 32bit
The platform specific details of mechanisms for implementing
confidential guest support may require setup at various points during
initialization. Thus, it's not really feasible to have a single cgs
initialization hook, but instead each mechanism needs its own
initialization calls in arch or machine specific code.
However, to make it harder to have a bug where a mechanism isn't
properly initialized under some circumstances, we want to have a
common place, late in boot, where we verify that cgs has been
initialized if it was requested.
This patch introduces a ready flag to the ConfidentialGuestSupport
base type to accomplish this, which we verify in
qemu_machine_creation_done().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Several architectures have mechanisms which are designed to protect
guest memory from interference or eavesdropping by a compromised
hypervisor. AMD SEV does this with in-chip memory encryption and
Intel's TDX can do similar things. POWER's Protected Execution
Framework (PEF) accomplishes a similar goal using an ultravisor and
new memory protection features, instead of encryption.
To (partially) unify handling for these, this introduces a new
ConfidentialGuestSupport QOM base class. "Confidential" is kind of vague,
but "confidential computing" seems to be the buzzword about these schemes,
and "secure" or "protected" are often used in connection to unrelated
things (such as hypervisor-from-guest or guest-from-guest security).
The "support" in the name is significant because in at least some of the
cases it requires the guest to take specific actions in order to protect
itself from hypervisor eavesdropping.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
