The Armv8.4 feature FEAT_IDST specifies that exceptions generated by
read accesses to the feature ID space should report a syndrome code
of 0x18 (EC_SYSTEMREGISTERTRAP) rather than 0x00 (EC_UNCATEGORIZED).
The feature ID space is defined to be:
op0 == 3, op1 == {0,1,3}, CRn == 0, CRm == {0-7}, op2 == {0-7}
In our implementation we might return the EC_UNCATEGORIZED syndrome
value for a system register access in four cases:
* no reginfo struct in the hashtable
* cp_access_ok() fails (ie ri->access doesn't permit the access)
* ri->accessfn returns CP_ACCESS_TRAP_UNCATEGORIZED at runtime
* ri->type includes ARM_CP_RAISES_EXC, and the readfn raises
an UNDEF exception at runtime
We have very few regdefs that set ARM_CP_RAISES_EXC, and none of
them are in the feature ID space. (In the unlikely event that any
are added in future they would need to take care of setting the
correct syndrome themselves.) This patch deals with the other
three cases, and enables FEAT_IDST for AArch64 -cpu max.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220509155457.3560724-1-peter.maydell@linaro.org
The description in the Arm ARM of the requirements of FEAT_BBM is
admirably clear on the guarantees it provides software, but slightly
more obscure on what that means for implementations. The description
of the equivalent SMMU feature in the SMMU specification (IHI0070D.b
section 3.21.1) is perhaps a bit more detailed and includes some
example valid implementation choices. (The SMMU version of this
feature is slightly tighter than the CPU version: the CPU is permitted
to raise TLB Conflict aborts in some situations that the SMMU may
not. This doesn't matter for QEMU because we don't want to do TLB
Conflict aborts anyway.)
The informal summary of FEAT_BBM is that it is about permitting an OS
to switch a range of memory between "covered by a huge page" and
"covered by a sequence of normal pages" without having to engage in
the 'break-before-make' dance that has traditionally been
necessary. The 'break-before-make' sequence is:
* replace the old translation table entry with an invalid entry
* execute a DSB insn
* execute a broadcast TLB invalidate insn
* execute a DSB insn
* write the new translation table entry
* execute a DSB insn
The point of this is to ensure that no TLB can simultaneously contain
TLB entries for the old and the new entry, which would traditionally
be UNPREDICTABLE (allowing the CPU to generate a TLB Conflict fault
or to use a random mishmash of values from the old and the new
entry). FEAT_BBM level 2 says "for the specific case where the only
thing that changed is the size of the block, the TLB is guaranteed
not to do weird things even if there are multiple entries for an
address", which means that software can now do:
* replace old translation table entry with new entry
* DSB
* broadcast TLB invalidate
* DSB
As the SMMU spec notes, valid ways to do this include:
* if there are multiple entries in the TLB for an address,
choose one of them and use it, ignoring the others
* if there are multiple entries in the TLB for an address,
throw them all out and do a page table walk to get a new one
QEMU's page table walk implementation for Arm CPUs already meets the
requirements for FEAT_BBM level 2. When we cache an entry in our TCG
TLB, we do so only for the specific (non-huge) page that the address
is in, and there is no way for the TLB data structure to ever have
more than one TLB entry for that page. (We handle huge pages only in
that we track what part of the address space is covered by huge pages
so that a TLB invalidate operation for an address in a huge page
results in an invalidation of the whole TLB.) We ignore the Contiguous
bit in page table entries, so we don't have to do anything for the
parts of FEAT_BBM that deal with changis to the Contiguous bit.
FEAT_BBM level 2 also requires that the nT bit in block descriptors
must be ignored; since commit 39a1fd2528 we do this.
It's therefore safe for QEMU to advertise FEAT_BBM level 2 by
setting ID_AA64MMFR2_EL1.BBM to 2.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220426160422.2353158-3-peter.maydell@linaro.org
The Arm FEAT_TTL architectural feature allows the guest to provide an
optional hint in an AArch64 TLB invalidate operation about which
translation table level holds the leaf entry for the address being
invalidated. QEMU's TLB implementation doesn't need that hint, and
we correctly ignore the (previously RES0) bits in TLB invalidate
operation values that are now used for the TTL field. So we can
simply advertise support for it in our 'max' CPU.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220426160422.2353158-2-peter.maydell@linaro.org
Add support for the TCG GICv4 to the virt board. For the board,
the GICv4 is very similar to the GICv3, with the only difference
being the size of the redistributor frame. The changes here are thus:
* calculating virt_redist_capacity correctly for GICv4
* changing various places which were "if GICv3" to be "if not GICv2"
* the commandline option handling
Note that using GICv4 reduces the maximum possible number of CPUs on
the virt board from 512 to 317, because we can now only fit half as
many redistributors into the redistributor regions we have defined.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220408141550.1271295-42-peter.maydell@linaro.org
This feature widens physical addresses (and intermediate physical
addresses for 2-stage translation) from 48 to 52 bits, when using
4k or 16k pages.
This introduces the DS bit to TCR_ELx, which is RES0 unless the
page size is enabled and supports LPA2, resulting in the effective
value of DS for a given table walk. The DS bit changes the format
of the page table descriptor slightly, moving the PS field out to
TCR so that all pages have the same sharability and repurposing
those bits of the page table descriptor for the highest bits of
the output address.
Do not yet enable FEAT_LPA2; we need extra plumbing to avoid
tickling an old kernel bug.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220301215958.157011-17-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This feature widens physical addresses (and intermediate physical
addresses for 2-stage translation) from 48 to 52 bits, when using
64k pages. The only thing left at this point is to handle the
extra bits in the TTBR and in the table descriptors.
Note that PAR_EL1 and HPFAR_EL2 are nominally extended, but we don't
mask out the high bits when writing to those registers, so no changes
are required there.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220301215958.157011-11-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This feature is relatively small, as it applies only to
64k pages and thus requires no additional changes to the
table descriptor walking algorithm, only a change to the
minimum TSZ (which is the inverse of the maximum virtual
address space size).
Note that this feature widens VBAR_ELx, but we already
treat the register as being 64 bits wide.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220301215958.157011-10-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
aspeed queue:
* Removal of the swift-bmc machine
* New Secure Boot Controller model
* Improvements on the rainier machine
* Various small cleanups
# gpg: Signature made Sun 27 Feb 2022 08:45:45 GMT
# gpg: using RSA key A0F66548F04895EBFE6B0B6051A343C7CFFBECA1
# gpg: Good signature from "Cédric Le Goater <clg@kaod.org>" [undefined]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg: There is no indication that the signature belongs to the owner.
# Primary key fingerprint: A0F6 6548 F048 95EB FE6B 0B60 51A3 43C7 CFFB ECA1
* remotes/legoater/tags/pull-aspeed-20220227:
aspeed/sdmc: Add trace events
aspeed/smc: Add an address mask on segment registers
aspeed: Introduce a create_pca9552() helper
aspeed: rainier: Add strap values taken from hardware
aspeed: rainier: Add i2c LED devices
ast2600: Add Secure Boot Controller model
arm: Remove swift-bmc machine
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
It was scheduled for removal in 7.0.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Add basic support for Pointer Authentication when running a KVM
guest and that the host supports it, loosely based on the SVE
support.
Although the feature is enabled by default when the host advertises
it, it is possible to disable it by setting the 'pauth=off' CPU
property. The 'pauth' comment is removed from cpu-features.rst,
as it is now common to both TCG and KVM.
Tested on an Apple M1 running 5.16-rc6.
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220107150154.2490308-1-maz@kernel.org
[PMM: fixed indentation]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Generally a guest needs an external source of randomness to properly
enable things like address space randomisation. However in a trusted
boot environment where the firmware will cryptographically verify
components having random data in the DTB will cause verification to
fail. Add a control knob so we can prevent this being added to the
system DTB.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: Jerome Forissier <jerome@forissier.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Message-Id: <20220105135009.1584676-22-alex.bennee@linaro.org>
Add -cpu a64fx to use A64FX processor when -machine virt option is
specified. In addition, add a64fx to the Supported guest CPU types
in the virt.rst document.
Signed-off-by: Shuuichirou Ishii <ishii.shuuichir@fujitsu.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
In rST markup, single backticks `like this` represent "interpreted
text", which can be handled as a bunch of different things if tagged
with a specific "role":
https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html#interpreted-text
(the most common one for us is "reference to a URL, which gets
hyperlinked").
The default "role" if none is specified is "title_reference",
intended for references to book or article titles, and it renders
into the HTML as <cite>...</cite> (usually comes out as italics).
This commit fixes various places in the manual which were
using single backticks when double backticks (for literal text)
were intended, and covers those files where only one or two
instances of these errors were made.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
In rST markup, single backticks `like this` represent "interpreted
text", which can be handled as a bunch of different things if tagged
with a specific "role":
https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html#interpreted-text
(the most common one for us is "reference to a URL, which gets
hyperlinked").
The default "role" if none is specified is "title_reference",
intended for references to book or article titles, and it renders
into the HTML as <cite>...</cite> (usually comes out as italics).
To format a literal (generally rendered as fixed-width font),
double-backticks are required.
cpu-features.rst consistently uses single backticks when double backticks
are required; correct it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20210726142338.31872-8-peter.maydell@linaro.org
