On 01/08/2021 16:59, Peter Maydell wrote:
On Sun, 1 Aug 2021 at 16:56, Mark Cave-Ayland
<mark.cave-ayl...@ilande.co.uk> wrote:
On 29/07/2021 15:51, Peter Maydell wrote:
On Thu, 29 Jul 2021 at 02:01, Richard Henderson
<richard.hender...@linaro.org> wrote:
We ought to have been recording the virtual address for reporting
to the guest trap handler. Mirror the SFSR FIXME from the sparc64
version of get_physical_address_data.
Cc: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk>
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
target/sparc/ldst_helper.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/target/sparc/ldst_helper.c b/target/sparc/ldst_helper.c
index 974afea041..7367b48c8b 100644
--- a/target/sparc/ldst_helper.c
+++ b/target/sparc/ldst_helper.c
@@ -1963,6 +1963,14 @@ void QEMU_NORETURN
sparc_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
SPARCCPU *cpu = SPARC_CPU(cs);
CPUSPARCState *env = &cpu->env;
+#ifdef TARGET_SPARC64
+ /* FIXME: ASI field in SFSR must be set */
+ env->dmmu.sfsr = SFSR_VALID_BIT; /* Fault status register */
+ env->dmmu.sfar = addr; /* Fault address register */
+#else
+ env->mmuregs[4] = addr;
+#endif
+
cpu_raise_exception_ra(env, TT_UNALIGNED, retaddr);
}
#endif
The architecture manual seems to be gratuitously opaque about
whether and where the fault address for an alignment fault gets
recorded, but Linux at least for 64-bit seems to pull it out of the
sfar, so I guess that's right.
Yeah, this part is actually contained within the UltraSPARC II specification -
it can
be found in section 6.4 "MMU-Related Faults and Traps" table 6-3 which
indicates that
for *_mem_address_not_aligned traps the D-SFSR and SFAR registers within the
MMU are
updated.
Do you know what 32-bit CPUs do? The Linux kernel sources don't help
here because they don't bother to report the fault address...
The SFSR and SFAR for the 32-bit sun4m machines is described in the Sun4m
Architecture manual section 4.4 "Synchronous Fault Registers". Unaligned access
behaviour isn't explicitly mentioned AFAICS but fault type 1 is "Invalid Address
Error" which seems like a possibility.
ATB,
Mark.
