| Message ID | 20210609174324.6621-1-sstabellini@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | xen/arm32: SPSR_hyp/SPSR | expand |
Hi Stefano, On 09/06/2021 18:43, Stefano Stabellini wrote: > SPSR_hyp is not meant to be accessed from Hyp mode (EL2); accesses > trigger UNPREDICTABLE behaviour. Xen should read/write SPSR instead. Please provide a reference to the spec. This helps reviewer and/or future developper to figure out quickly where this comes from. > > This fixes booting Xen/arm32 on QEMU. > > Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com> With the reference added: Reviewed-by: Julien Grall <jgrall@amazon.com> Cheers,
On Wed, Jun 09, 2021 at 06:53:02PM +0100, Julien Grall wrote: > Hi Stefano, > > On 09/06/2021 18:43, Stefano Stabellini wrote: > > SPSR_hyp is not meant to be accessed from Hyp mode (EL2); accesses > > trigger UNPREDICTABLE behaviour. Xen should read/write SPSR instead. > > Please provide a reference to the spec. This helps reviewer and/or future > developper to figure out quickly where this comes from. > > > > > This fixes booting Xen/arm32 on QEMU. > > > > Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com> > > With the reference added: > > Reviewed-by: Julien Grall <jgrall@amazon.com> Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> Cheers, Edgar
On Wed, 9 Jun 2021, Julien Grall wrote: > Hi Stefano, > > On 09/06/2021 18:43, Stefano Stabellini wrote: > > SPSR_hyp is not meant to be accessed from Hyp mode (EL2); accesses > > trigger UNPREDICTABLE behaviour. Xen should read/write SPSR instead. > > Please provide a reference to the spec. This helps reviewer and/or future > developper to figure out quickly where this comes from. > > > > > This fixes booting Xen/arm32 on QEMU. > > > > Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com> > > With the reference added: > > Reviewed-by: Julien Grall <jgrall@amazon.com> Thanks! I added: ARM DDI 0487D.b page G8-5993 and committed it
diff --git a/xen/arch/arm/arm32/entry.S b/xen/arch/arm/arm32/entry.S index f2f1bc7a31..4e421109db 100644 --- a/xen/arch/arm/arm32/entry.S +++ b/xen/arch/arm/arm32/entry.S @@ -170,7 +170,7 @@ ENDPROC(prepare_context_from_guest) mrc CP32(r11, HSR) /* Save exception syndrome */ str r11, [sp, #UREGS_hsr] - mrs r11, SPSR_hyp + mrs r11, SPSR str r11, [sp, #UREGS_cpsr] /* @@ -395,7 +395,7 @@ return_to_hypervisor: ldr r11, [sp, #UREGS_pc] msr ELR_hyp, r11 ldr r11, [sp, #UREGS_cpsr] - msr SPSR_hyp, r11 + msr SPSR, r11 #ifdef CONFIG_ARM32_HARDEN_BRANCH_PREDICTOR /* * Hardening branch predictor may require to setup a different
SPSR_hyp is not meant to be accessed from Hyp mode (EL2); accesses trigger UNPREDICTABLE behaviour. Xen should read/write SPSR instead. This fixes booting Xen/arm32 on QEMU. Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com> --- xen/arch/arm/arm32/entry.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)