The max count in itrigger can be 0x3FFF, which will cause a no trivial
translation and execution overload.
When icount is enabled, QEMU provides API that can fetch guest
instruction number. Thus, we can set an timer for itrigger with
the count as deadline.
Only when timer expires or priviledge mode changes, do lazy update
to count.
Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20221013062946.7530-3-zhiwei_liu@linux.alibaba.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
When icount is not enabled, there is no API in QEMU that can get the
guest instruction number.
Translate the guest code in a way that each TB only has one instruction.
After executing the instruction, decrease the count by 1 until it reaches 0
where the itrigger fires.
Note that only when priviledge matches the itrigger configuration,
the count will decrease.
Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20221013062946.7530-2-zhiwei_liu@linux.alibaba.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Only the pmp index that be checked by pmp_hart_has_privs can be used
by pmp_get_tlb_size to avoid an error pmp index.
Before modification, we may use an error pmp index. For example,
we check address 0x4fc, and the size 0x4 in pmp_hart_has_privs. If there
is an pmp rule, valid range is [0x4fc, 0x500), then pmp_hart_has_privs
will return true;
However, this checked pmp index is discarded as pmp_hart_has_privs
return bool value. In pmp_is_range_in_tlb, it will traverse all pmp
rules. The tlb_sa will be 0x0, and tlb_ea will be 0xfff. If there is
a pmp rule [0x10, 0x14), it will be misused as it is legal in
pmp_get_tlb_size.
As we have already known the correct pmp index, just remove the
remove the pmp_is_range_in_tlb and get tlb size directly from
pmp_get_tlb_size.
Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20221012060016.30856-1-zhiwei_liu@linux.alibaba.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The riscv target incorrectly enabled semihosting always, whether the
user asked for it or not. Call semihosting_enabled() passing the
correct value to the is_userspace argument, which fixes this and also
handles the userspace=on argument. Because we do this at translate
time, we no longer need to check the privilege level in
riscv_cpu_do_interrupt().
Note that this is a behaviour change: we used to default to
semihosting being enabled, and now the user must pass
"-semihosting-config enable=on" if they want it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220822141230.3658237-8-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
vstimecmp CSR allows the guest OS or to program the next guest timer
interrupt directly. Thus, hypervisor no longer need to inject the
timer interrupt to the guest if vstimecmp is used. This was ratified
as a part of the Sstc extension.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-Id: <20220824221357.41070-4-atishp@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
According to v-spec, mask agnostic behavior can be either kept as
undisturbed or set elements' bits to all 1s. To distinguish the
difference of mask policies, QEMU should be able to simulate the mask
agnostic behavior as "set mask elements' bits to all 1s".
There are multiple possibility for agnostic elements according to
v-spec. The main intent of this patch-set tries to add option that
can distinguish between mask policies. Setting agnostic elements to
all 1s allows QEMU to express this.
This is the first commit regarding the optional mask agnostic
behavior. Follow-up commits will add this optional behavior
for all rvv instructions.
Signed-off-by: eop Chen <eop.chen@sifive.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <165570784143.17634.35095816584573691-1@git.sr.ht>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The latest AIA draft v0.3.0 defines a relatively simpler scheme for
default priority assignments where:
1) local interrupts 24 to 31 and 48 to 63 are reserved for custom use
and have implementation specific default priority.
2) remaining local interrupts 0 to 23 and 32 to 47 have a recommended
(not mandatory) priority assignments.
We update the default priority table and hviprio mapping as-per above.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220616031543.953776-3-apatel@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Perform the cleanup in the FIXME comment in common_semi_gdb_syscall.
Do not modify guest registers until the syscall is complete,
which in the gdbstub case is asynchronous.
In the synchronous non-gdbstub case, use common_semi_set_ret
to set the result. Merge set_swi_errno into common_semi_cb.
Rely on the latter for combined return value / errno setting.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
According to v-spec, tail agnostic behavior can be either kept as
undisturbed or set elements' bits to all 1s. To distinguish the
difference of tail policies, QEMU should be able to simulate the tail
agnostic behavior as "set tail elements' bits to all 1s".
There are multiple possibility for agnostic elements according to
v-spec. The main intent of this patch-set tries to add option that
can distinguish between tail policies. Setting agnostic elements to
all 1s allows QEMU to express this.
This is the first commit regarding the optional tail agnostic
behavior. Follow-up commits will add this optional behavior
for all rvv instructions.
Signed-off-by: eop Chen <eop.chen@sifive.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <165449614532.19704.7000832880482980398-5@git.sr.ht>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Whether or not VSEIP is pending isn't reflected in env->mip and must
instead be determined from hstatus.vgein and hgeip. As a result a
CPU in WFI won't wake on a VSEIP, which violates the WFI behavior as
specified in the privileged ISA. Just use riscv_cpu_all_pending()
instead, which already accounts for VSEIP.
Signed-off-by: Andrew Bresticker <abrestic@rivosinc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220531210544.181322-1-abrestic@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Currently, the [m|s]tval CSRs are set with trapping instruction encoding
only for illegal instruction traps taken at the time of instruction
decoding.
In RISC-V world, a valid instructions might also trap as illegal or
virtual instruction based to trapping bits in various CSRs (such as
mstatus.TVM or hstatus.VTVM).
We improve setting of [m|s]tval CSRs for all types of illegal and
virtual instruction traps.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220511144528.393530-4-apatel@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Currently, QEMU does not set hstatus.GVA bit for traps taken from
HS-mode into HS-mode which breaks the Xvisor nested MMU test suite
on QEMU. This was working previously.
This patch updates riscv_cpu_do_interrupt() to fix the above issue.
Fixes: 86d0c45739 ("target/riscv: Fixup setting GVA")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220511144528.393530-3-apatel@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
RISC-V privilege spec defines that mtime is exposed as a memory-mapped
machine-mode read-write register. However, as QEMU uses host monotonic
timer as timer source, this makes mtime to be read-only in RISC-V
ACLINT.
This patch makes mtime to be writable by recording the time delta value
between the mtime value to be written and the timer value at the time
mtime is written. Time delta value is then added back whenever the timer
value is retrieved.
Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Jim Shu <jim.shu@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220420080901.14655-4-frank.chang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The AIA spec defines programmable 8-bit priority for each local interrupt
at M-level, S-level and VS-level so we extend local interrupt processing
to consider AIA interrupt priorities. The AIA CSRs which help software
configure local interrupt priorities will be added by subsequent patches.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220204174700.534953-10-anup@brainfault.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The guest external interrupts from an interrupt controller are
delivered only when the Guest/VM is running (i.e. V=1). This means
any guest external interrupt which is triggered while the Guest/VM
is not running (i.e. V=0) will be missed on QEMU resulting in Guest
with sluggish response to serial console input and other I/O events.
To solve this, we check and inject interrupt after setting V=1.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Message-id: 20220204174700.534953-5-anup@brainfault.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Current xlen has been used in helper functions and many other places.
The computation of current xlen is not so trivial, so that we should
recompute it as little as possible.
Fortunately, xlen only changes in very seldom cases, such as exception,
misa write, mstatus write, cpu reset, migration load. So that we can only
recompute xlen in this places and cache it into CPURISCVState.
Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220120122050.41546-6-zhiwei_liu@c-sky.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The stval and mtval registers can optionally contain the faulting
instruction on an illegal instruction exception. This patch adds support
for setting the stval and mtval registers.
The RISC-V spec states that "The stval register can optionally also be
used to return the faulting instruction bits on an illegal instruction
exception...". In this case we are always writing the value on an
illegal instruction.
This doesn't match all CPUs (some CPUs won't write the data), but in
QEMU let's just populate the value on illegal instructions. This won't
break any guest software, but will provide more information to guests.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Message-id: 20211220064916.107241-4-alistair.francis@opensource.wdc.com
The fallback code in cpu_loop_exit_sigsegv is sufficient
for riscv linux-user.
Remove the code from cpu_loop that raised SIGSEGV.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
There is no need to "force an hs exception" as the current privilege
level, the state of the global ie and of the delegation registers should
be enough to route the interrupt to the appropriate privilege level in
riscv_cpu_do_interrupt. The is true for both asynchronous and
synchronous exceptions, specifically, guest page faults which must be
hardwired to zero hedeleg. As such the hs_force_except mechanism can be
removed.
Signed-off-by: Jose Martins <josemartins90@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20211026145126.11025-3-josemartins90@gmail.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
VS interrupts (2, 6, 10) were not correctly forwarded to hs-mode when
not delegated in hideleg (which was not being taken into account). This
was mainly because hs level sie was not always considered enabled when
it should. The spec states that "Interrupts for higher-privilege modes,
y>x, are always globally enabled regardless of the setting of the global
yIE bit for the higher-privilege mode." and also "For purposes of
interrupt global enables, HS-mode is considered more privileged than
VS-mode, and VS-mode is considered more privileged than VU-mode". Also,
vs-level interrupts were not being taken into account unless V=1, but
should be unless delegated.
Finally, there is no need for a special case for to handle vs interrupts
as the current privilege level, the state of the global ie and of the
delegation registers should be enough to route all interrupts to the
appropriate privilege level in riscv_cpu_do_interrupt.
Signed-off-by: Jose Martins <josemartins90@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20211026145126.11025-2-josemartins90@gmail.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
