mirror of https://github.com/xemu-project/xemu.git
![]() raise_mmu_exception(), as is today, is prioritizing guest page faults by
checking first if virt_enabled && !first_stage, and then considering the
regular inst/load/store faults.
There's no mention in the spec about guest page fault being a higher
priority that PMP faults. In fact, privileged spec section 3.7.1 says:
"Attempting to fetch an instruction from a PMP region that does not have
execute permissions raises an instruction access-fault exception.
Attempting to execute a load or load-reserved instruction which accesses
a physical address within a PMP region without read permissions raises a
load access-fault exception. Attempting to execute a store,
store-conditional, or AMO instruction which accesses a physical address
within a PMP region without write permissions raises a store
access-fault exception."
So, in fact, we're doing it wrong - PMP faults should always be thrown,
regardless of also being a first or second stage fault.
The way riscv_cpu_tlb_fill() and get_physical_address() work is
adequate: a TRANSLATE_PMP_FAIL error is immediately reported and
reflected in the 'pmp_violation' flag. What we need is to change
raise_mmu_exception() to prioritize it.
Reported-by: Joseph Chan <jchan@ventanamicro.com>
Fixes:
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.. | ||
alpha | ||
arm | ||
avr | ||
cris | ||
hexagon | ||
hppa | ||
i386 | ||
loongarch | ||
m68k | ||
microblaze | ||
mips | ||
openrisc | ||
ppc | ||
riscv | ||
rx | ||
s390x | ||
sh4 | ||
sparc | ||
tricore | ||
xtensa | ||
Kconfig | ||
meson.build |