The RISC-V ISA spec version 1.09.1 has been deprecated in QEMU since
4.1. It's not commonly used so let's remove support for it.
Backports commit 1a9540d1f1a9c5022d9273d0244e5809679dd33b from qemu
As-per RISC-V H-Extension v0.5 draft, the Stage2 SV32 page table has
12bits of VPN[1] and 10bits of VPN[0]. The additional 2bits in VPN[1]
is required to handle the 34bit intermediate physical address coming
from Stage1 SV32 page table. The 12bits of VPN[1] implies that Stage2
SV32 level-0 page table will be 16KB in size with total 4096 enteries
where each entry maps 4MB of memory (same as Stage1 SV32 page table).
The get_physical_address() function is broken for Stage2 SV32 level-0
page table because it incorrectly computes output physical address for
Stage2 SV32 level-0 page table entry.
The root cause of the issue is that get_physical_address() uses the
"widened" variable to compute level-0 physical address mapping which
changes level-0 mapping size (instead of 4MB). We should use the
"widened" variable only for computing index of Stage2 SV32 level-0
page table.
Backports commit ee79e7cd47ef47074d7c20c221321c5d31d3683d from qemu
Take the result of stage-1 and stage-2 page table walks and AND the two
protection flags together. This way we require both to set permissions
instead of just stage-2.
Backports commit 8f67cd6db7375f9133d900b13b300931fbc2e1d8 from qemu
When doing the fist of a two stage lookup (Hypervisor extensions) don't
set the current protection flags from the second stage lookup of the
base address PTE.
Backports commit 384728905441279e54fa3d714b11bf1b1bcbfd27 from qemu
Currently riscv_cpu_local_irq_pending is used to find out pending
interrupt and VS mode interrupts are being shifted to represent
S mode interrupts in this function. So when the cause returned by
this function is passed to riscv_cpu_do_interrupt to actually
forward the interrupt, the VS mode forwarding check does not work
as intended and interrupt is actually forwarded to hypervisor. This
patch fixes this issue.
Backports commit c5969a3a3c2cb9ea02ffb7e86acb059d3cf8c264 from qemu
Currently, TIME CSRs are emulated only for user-only mode. This
patch add TIME CSRs emulation for privileged mode.
For privileged mode, the TIME CSRs will return value provided
by rdtime callback which is registered by QEMU machine/platform
emulation (i.e. CLINT emulation). If rdtime callback is not
available then the monitor (i.e. OpenSBI) will trap-n-emulate
TIME CSRs in software.
We see 25+% performance improvement in hackbench numbers when
TIME CSRs are not trap-n-emulated.
Backports commit c695724868ce4049fd79c5a509880dbdf171e744 from qemu
Add a helper macro MSTATUS_MPV_ISSET() which will determine if the
MSTATUS_MPV bit is set for both 32-bit and 64-bit RISC-V.
Backports commit e44b50b5b2e508fdd24915ab0e44ac49685e1de3 from qemu
When the Hypervisor extension is in use we only enable floating point
support when both status and vsstatus have enabled floating point
support.
Backports commit 29409c1d921d607873268671bf11a088efb5558e from qemu
To ensure our TLB isn't out-of-date we flush it on all virt mode
changes. Unlike priv mode this isn't saved in the mmu_idx as all
guests share V=1. The easiest option is just to flush on all changes.
Backports commit eccc5a12c2fd1c646c69a1e7de29183b7a559973 from qemu
Add a FORCE_HS_EXCEP mode to the RISC-V virtulisation status. This bit
specifies if an exeption should be taken to HS mode no matter the
current delegation status. This is used when an exeption must be taken
to HS mode, such as when handling interrupts.
Backports commit c7b1bbc80fc2af17395d3986c346fd2307e57829 from qemu
This prevents a load reservation from being placed in one context/process,
then being used in another, resulting in an SC succeeding incorrectly and
breaking atomics.
Backports commit c13b169f1a3dd158d6c75727cdc388f95988db39 from qemu
The PMP should be checked when doing a page table walk, and report access
fault exception if the to-be-read PTE failed the PMP check.
Backports commit 1f447aec787bfbbd078afccae44fc4c92acb4fed from qemu
The current PMP check function checks for env->priv which is not the effective
memory privilege mode.
For example, mstatus.MPRV could be set while executing in M-Mode, and in that
case the privilege mode for the PMP check should be S-Mode rather than M-Mode
(in env->priv) if mstatus.MPP == PRV_S.
This patch passes the effective memory privilege mode to the PMP check.
Functions that call the PMP check should pass the correct memory privilege mode
after reading mstatus' MPRV/MPP or hstatus.SPRV (if Hypervisor mode exists).
Backports commit cc0fdb298517ce56c770803447f8b02a90271152 from qemu
Section 3.6 in RISC-V v1.10 privilege specification states that PMP violations
report "access exceptions." The current PMP implementation has
a bug which wrongly reports "page exceptions" on PMP violations.
This patch fixes this bug by reporting the correct PMP access exceptions
trap values.
Backports commit 635b0b0ea39a13d1a3df932452e5728aebbb3f6e from qemu
The current implementation unnecessarily checks for PMP even if MMU translation
failed. This may trigger a wrong PMP access exception instead of
a page exception.
For example, the very first instruction fetched after the first satp write in
S-Mode will trigger a PMP access fault instead of an instruction fetch page
fault.
This patch prioritises MMU exceptions over PMP exceptions and only checks for
PMP if MMU translation succeeds. This patch is required for future commits
that properly report PMP exception violations if PTW succeeds.
Backports commit e0f8fa72deba7ac7a7ae06ba25e6498aaad93ace from qemu
This patch adds support for the riscv_cpu_unassigned_access call
and will raise a load or store access fault.
Backports commit cbf5827693addaff4e4d2102afedbf078a204eb2 from qemu
Cleanup in the boilerplate that each target must define.
Replace riscv_env_get_cpu with env_archcpu. The combination
CPU(riscv_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.
Backports commit 3109cd98a6c0c618189b38a83a8aa29cb20acbce from qemu
We can now use the CPUClass hook instead of a named function.
Create a static tlb_fill function to avoid other changes within
cputlb.c. This also isolates the asserts within. Remove the
named tlb_fill function from all of the targets.
Backports commit c319dc13579a92937bffe02ad2c9f1a550e73973 from qemu
Note that env->pc is removed from the qemu_log as that value is garbage.
The PC isn't recovered until cpu_restore_state, called from
cpu_loop_exit_restore, called from riscv_raise_exception.
Backports commit 8a4ca3c10a96be6ed7f023b685b688c4d409bbcb from qemu
If vectored interrupts are enabled (bits[1:0]
of mtvec/stvec == 1) then use the following
logic for trap entry address calculation:
pc = mtvec + cause * 4
In addition to adding support for vectored interrupts
this patch simplifies the interrupt delivery logic
by making sync/async cause decoding and encoding
steps distinct.
The cause code and the sign bit indicating sync/async
is split at the beginning of the function and fixed
cause is renamed to cause. The MSB setting for async
traps is delayed until setting mcause/scause to allow
redundant variables to be eliminated. Some variables
are renamed for conciseness and moved so that decls
are at the start of the block.
Backports commit acbbb94e5730c9808830938e869d243014e2923a from qemu
This effectively changes riscv_cpu_update_mip
from edge to level. i.e. cpu_interrupt or
cpu_reset_interrupt are called regardless of
the current interrupt level.
Fixes WFI doesn't return when a IPI is issued:
- https://github.com/riscv/riscv-qemu/issues/132
To test:
1) Apply RISC-V Linux CPU hotplug patch:
- http://lists.infradead.org/pipermail/linux-riscv/2018-May/000603.html
2) Enable CONFIG_CPU_HOTPLUG in linux .config
3) Try to offline and online cpus:
echo 1 > /sys/devices/system/cpu/cpu2/online
echo 0 > /sys/devices/system/cpu/cpu2/online
echo 1 > /sys/devices/system/cpu/cpu2/online
Backports commit d26f5a423438e579d3ff0ca35e44edb966a36233 from qemu
We can't allow the supervisor to control SEIP as this would allow the
supervisor to clear a pending external interrupt which will result in
lost a interrupt in the case a PLIC is attached. The SEIP bit must be
hardware controlled when a PLIC is attached.
This logic was previously hard-coded so SEIP was always masked even
if no PLIC was attached. This patch adds riscv_cpu_claim_interrupts
so that the PLIC can register control of SEIP. In the case of models
without a PLIC (spike), the SEIP bit remains software controlled.
This interface allows for hardware control of supervisor timer and
software interrupts by other interrupt controller models.
Backports commit e3e7039cc24ecf47d81c091e8bb04552d6564ad8 from qemu
This ports over the RISC-V architecture from Qemu. This is currently a
very barebones transition. No code hooking or any fancy stuff.
Currently, you can feed it instructions and query the CPU state itself.
This also allows choosing whether or not RISC-V 32-bit or RISC-V 64-bit
is desirable through Unicorn's interface as well.
Extremely basic examples of executing a single instruction have been
added to the samples directory to help demonstrate how to use the basic
functionality.
