FEAT_PAN3 adds an EPAN bit to SCTLR_EL1 and SCTLR_EL2, which allows
the PAN bit to make memory non-privileged-read/write if it is
user-executable as well as if it is user-read/write.
Implement this feature and enable it in the AArch64 'max' CPU.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230331145045.2584941-4-peter.maydell@linaro.org
This patch adds WDT to Allwinner-H3 and Orangepi-PC.
WDT is added as an overlay to the Timer module memory area.
Signed-off-by: Strahinja Jankovic <strahinja.p.jankovic@gmail.com>
Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Message-id: 20230326202256.22980-4-strahinja.p.jankovic@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This patch adds WDT to Allwinner-A10 and Cubieboard.
WDT is added as an overlay to the Timer module memory map.
Signed-off-by: Strahinja Jankovic <strahinja.p.jankovic@gmail.com>
Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Message-id: 20230326202256.22980-3-strahinja.p.jankovic@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The markup for the Arm CPU feature documentation is incorrect,
and results in the HTML not rendering correctly -- the first
line of each description is rendered in boldface as if it
were part of the option name.
Reformat to match the styling used in cpu-models-x86.rst.inc.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1479
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20230316105808.1414003-1-peter.maydell@linaro.org
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
This patch support Tiogapass in QEMU environment.
and introduced EEPROM BMC FRU data support "add tiogapass_bmc_fruid data"
along with the machine support.
Signed-off-by: Karthikeyan Pasupathi <pkarthikeyan1509@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
[ clg: - commit log topic update
- checkpatch issues
- Documentation update ]
Message-Id: <20230216184342.253868-1-pkarthikeyan1509@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
This patch support Yosemitev2 in QEMU environment.
and introduced EEPROM BMC FRU data support "add fbyv2_bmc_fruid data"
along with the machine support.
Signed-off-by: Karthikeyan Pasupathi <pkarthikeyan1509@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
[ clg: - commit log topic update
- Documentation update ]
Message-Id: <20230216133326.216017-1-pkarthikeyan1509@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
This affects both system and user mode emulation so we should probably
list it up front.
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230124180127.1881110-21-alex.bennee@linaro.org>
This patch implements Allwinner TWI/I2C controller emulation. Only
master-mode functionality is implemented.
The SPL boot for Cubieboard expects AXP209 PMIC on TWI0/I2C0 bus, so this is
first part enabling the TWI/I2C bus operation.
Since both Allwinner A10 and H3 use the same module, it is added for
both boards.
Docs are also updated for Cubieboard and Orangepi-PC board to indicate
I2C availability.
Signed-off-by: Strahinja Jankovic <strahinja.p.jankovic@gmail.com>
Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Message-id: 20221226220303.14420-4-strahinja.p.jankovic@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Olimex makes a series of low-cost STM32 boards. This commit introduces
the minimum setup to support SMT32-H405. See [1] for details
[1] https://www.olimex.com/Products/ARM/ST/STM32-H405/
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20221230145733.200496-3-balbi@kernel.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Update the ID registers for TCG's '-cpu max' to report the
FEAT_EVT Enhanced Virtualization Traps support.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
The Cortex-A55 is one of the newer armv8.2+ CPUs; in particular
it supports the Privileged Access Never (PAN) feature. Add
a model of this CPU, so you can use a CPU type on the virt
board that models a specific real hardware CPU, rather than
having to use the QEMU-specific "max" CPU type.
Signed-off-by: Timofey Kutergin <tkutergin@gmail.com>
Message-id: 20221121150819.2782817-1-tkutergin@gmail.com
[PMM: tweaked commit message]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The 3 high memory regions are usually enabled by default, but they may
be not used. For example, VIRT_HIGH_GIC_REDIST2 isn't needed by GICv2.
This leads to waste in the PA space.
Add properties ("highmem-redists", "highmem-ecam", "highmem-mmio") to
allow users selectively disable them if needed. After that, the high
memory region for GICv3 or GICv4 redistributor can be disabled by user,
the number of maximal supported CPUs needs to be calculated based on
'vms->highmem_redists'. The follow-up error message is also improved
to indicate if the high memory region for GICv3 and GICv4 has been
enabled or not.
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Message-id: 20221029224307.138822-8-gshan@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
After the improvement to high memory region address assignment is
applied, the memory layout can be changed, introducing possible
migration breakage. For example, VIRT_HIGH_PCIE_MMIO memory region
is disabled or enabled when the optimization is applied or not, with
the following configuration. The configuration is only achievable by
modifying the source code until more properties are added to allow
users selectively disable those high memory regions.
pa_bits = 40;
vms->highmem_redists = false;
vms->highmem_ecam = false;
vms->highmem_mmio = true;
# qemu-system-aarch64 -accel kvm -cpu host \
-machine virt-7.2,compact-highmem={on, off} \
-m 4G,maxmem=511G -monitor stdio
Region compact-highmem=off compact-highmem=on
----------------------------------------------------------------
MEM [1GB 512GB] [1GB 512GB]
HIGH_GIC_REDISTS2 [512GB 512GB+64MB] [disabled]
HIGH_PCIE_ECAM [512GB+256MB 512GB+512MB] [disabled]
HIGH_PCIE_MMIO [disabled] [512GB 1TB]
In order to keep backwords compatibility, we need to disable the
optimization on machine, which is virt-7.1 or ealier than it. It
means the optimization is enabled by default from virt-7.2. Besides,
'compact-highmem' property is added so that the optimization can be
explicitly enabled or disabled on all machine types by users.
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Tested-by: Zhenyu Zhang <zhenyzha@redhat.com>
Message-id: 20221029224307.138822-7-gshan@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Most of them were found and fixed using codespell.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20221030105944.311940-1-sw@weilnetz.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Perform the atomic update for hardware management of the access flag.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20221024051851.3074715-13-richard.henderson@linaro.org
[PMM: Fix accidental PROT_WRITE to PAGE_WRITE; add missing
main-loop.h include]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
FEAT_E0PD adds new bits E0PD0 and E0PD1 to TCR_EL1, which allow the
OS to forbid EL0 access to half of the address space. Since this is
an EL0-specific variation on the existing TCR_ELx.{EPD0,EPD1}, we can
implement it entirely in aa64_va_parameters().
This requires moving the existing regime_is_user() to internals.h
so that the code in helper.c can get at it.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20221021160131.3531787-1-peter.maydell@linaro.org
FEAT_GTG is a change tho the ID register ID_AA64MMFR0_EL1 so that it
can report a different set of supported granule (page) sizes for
stage 1 and stage 2 translation tables. As of commit c20281b2a5
we already report the granule sizes that way for '-cpu max', and now
we also correctly make attempts to use unimplemented granule sizes
fail, so we can report the support of the feature in the
documentation.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20221003162315.2833797-4-peter.maydell@linaro.org
openpower.xyz was retired some time ago. The OpenBMC Jenkins is where
images can be found these days.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Hao Wu <wuhaotsh@google.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20221004050042.22681-1-joel@jms.id.au
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Update the ID registers for TCG's '-cpu max' to report a FEAT_PMUv3p5
compliant PMU.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220822132358.3524971-11-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The architectural feature FEAT_ETS (Enhanced Translation
Synchronization) is a set of tightened guarantees about memory
ordering involving translation table walks:
* if memory access RW1 is ordered-before memory access RW2 then it
is also ordered-before any translation table walk generated by RW2
that generates a translation fault, address size fault or access
fault
* TLB maintenance on non-exec-permission translations is guaranteed
complete after a DSB (ie it does not need the context
synchronization event that you have to have if you don’t have
FEAT_ETS)
For QEMU’s implementation we don’t reorder translation table walk
accesses, and we guarantee to finish the TLB maintenance as soon as
the TLB op is done (the tlb_flush functions will complete at the end
of the TLB, and TLB ops always end the TB because they’re sysreg
writes).
So we’re already compliant and all we need to do is say so in the ID
registers for the 'max' CPU.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220819110052.2942289-6-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Add cortex A35 core and enable it for virt board.
Signed-off-by: Hao Wu <wuhaotsh@google.com>
Reviewed-by: Joe Komlodi <komlodi@google.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220819002015.1663247-1-wuhaotsh@google.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220707163720.1421716-5-berrange@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Some more controllers have been modeled recently. Reflect that in the
list of supported devices. New machines were also added.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Peter Delevoryas <peter@pjd.dev>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Message-Id: <20220706172131.809255-1-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Peter Delevoryas <peter@pjd.dev>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
[ clg: - fixed URL links
- Moved Facebook Yosemite section at the end of the file ]
Message-Id: <20220705191400.41632-10-peter@pjd.dev>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Note that SME remains effectively disabled for user-only,
because we do not yet set CPACR_EL1.SMEN. This needs to
wait until the kernel ABI is implemented.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220708151540.18136-33-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
In 60592cfed2 ("hw/arm/virt: dt: add kaslr-seed property"), the
kaslr-seed property was added, but the equally as important rng-seed
property was forgotten about, which has identical semantics for a
similar purpose. This commit implements it in exactly the same way as
kaslr-seed. It then changes the name of the disabling option to reflect
that this has more to do with randomness vs determinism, rather than
something particular about kaslr.
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
[PMM: added deprecated.rst section for the deprecation]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Mirror the properties for SVE. The main difference is
that any arbitrary set of powers of 2 may be supported,
and not the stricter constraints that apply to SVE.
Include a property to control FEAT_SME_FA64, as failing
to restrict the runtime to the proper subset of insns
could be a major point for bugs.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20220620175235.60881-18-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The FEAT_DoubleFault extension adds the following:
* All external aborts on instruction fetches and translation table
walks for instruction fetches must be synchronous. For QEMU this
is already true.
* SCR_EL3 has a new bit NMEA which disables the masking of SError
interrupts by PSTATE.A when the SError interrupt is taken to EL3.
For QEMU we only need to make the bit writable, because we have no
sources of SError interrupts.
* SCR_EL3 has a new bit EASE which causes synchronous external
aborts taken to EL3 to be taken at the same entry point as SError.
(Note that this does not mean that they are SErrors for purposes
of PSTATE.A masking or that the syndrome register reports them as
SErrors: it just means that the vector offset is different.)
* The existing SCTLR_EL3.IESB has an effective value of 1 when
SCR_EL3.NMEA is 1. For QEMU this is a no-op because we don't need
different behaviour based on IESB (we don't need to do anything to
ensure that error exceptions are synchronized).
So for QEMU the things we need to change are:
* Make SCR_EL3.{NMEA,EASE} writable
* When taking a synchronous external abort at EL3, adjust the
vector entry point if SCR_EL3.EASE is set
* Advertise the feature in the ID registers
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220531151431.949322-1-peter.maydell@linaro.org
The architectural feature RASv1p1 introduces the following new
features:
* new registers ERXPFGCDN_EL1, ERXPFGCTL_EL1 and ERXPFGF_EL1
* new bits in the fine-grained trap registers that control traps
for these new registers
* new trap bits HCR_EL2.FIEN and SCR_EL3.FIEN that control traps
for ERXPFGCDN_EL1, ERXPFGCTL_EL1, ERXPFGP_EL1
* a larger number of the ERXMISC<n>_EL1 registers
* the format of ERR<n>STATUS registers changes
The architecture permits that if ERRIDR_EL1.NUM is 0 (as it is for
QEMU) then all these new registers may UNDEF, and the HCR_EL2.FIEN
and SCR_EL3.FIEN bits may be RES0. We don't have any ERR<n>STATUS
registers (again, because ERRIDR_EL1.NUM is 0). QEMU does not yet
implement the fine-grained-trap extension. So there is nothing we
need to implement to be compliant with the feature spec. Make the
'max' CPU report the feature in its ID registers, and document it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220531114258.855804-1-peter.maydell@linaro.org
In commit 5814d587fe we added support for emulating
FEAT_HCX (Support for the HCRX_EL2 register). However we
forgot to add it to the list in emulated.rst. Correct the
omission.
Fixes: 5814d587fe ("target/arm: Enable FEAT_HCX for -cpu max")
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220520084320.424166-1-peter.maydell@linaro.org
Add fby35 to the list of Aspeed boards.
Signed-off-by: Peter Delevoryas <pdel@fb.com>
Message-Id: <20220506193354.990532-2-pdel@fb.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
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
Enable the FEAT_S2FWB for -cpu max. Since FEAT_S2FWB requires that
CLIDR_EL1.{LoUU,LoUIS} are zero, we explicitly squash these (the
inherited CLIDR_EL1 value from the Cortex-A57 has them as 1).
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220505183950.2781801-5-peter.maydell@linaro.org
Enable the n1 for virt and sbsa board use.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-25-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Enable the a76 for virt and sbsa board use.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-24-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This extension concerns not merging memory access, which TCG does
not implement. Thus we can trivially enable this feature.
Add a comment to handle_hint for the DGH instruction, but no code.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-23-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This extension concerns cache speculation, which TCG does
not implement. Thus we can trivially enable this feature.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-22-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
There is no branch prediction in TCG, therefore there is no
need to actually include the context number into the predictor.
Therefore all we need to do is add the state for SCXTNUM_ELx.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-21-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This extension concerns branch speculation, which TCG does
not implement. Thus we can trivially enable this feature.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-20-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This feature is AArch64 only, and applies to physical SErrors,
which QEMU does not implement, thus the feature is a nop.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-19-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-18-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This extension concerns changes to the External Debug interface,
with Secure and Non-secure access to the debug registers, and all
of it is outside the scope of QEMU. Indicating support for this
is mandatory with FEAT_SEL2, which we do implement.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-13-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The only portion of FEAT_Debugv8p2 that is relevant to QEMU
is CONTEXTIDR_EL2, which is also conditionally implemented
with FEAT_VHE. The rest of the debug extension concerns the
External debug interface, which is outside the scope of QEMU.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220506180242.216785-12-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <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
Describe that the gic-version influences the maximum number of CPUs.
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Message-id: 20220413231456.35811-1-heinrich.schuchardt@canonical.com
[PMM: minor punctuation tweaks]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
