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Re: [PATCH v3 5/6] target/arm: Do memory type alignment check when trans
From: |
Jonathan Cameron |
Subject: |
Re: [PATCH v3 5/6] target/arm: Do memory type alignment check when translation disabled |
Date: |
Tue, 16 Apr 2024 16:11:11 +0100 |
On Fri, 1 Mar 2024 10:41:09 -1000
Richard Henderson <richard.henderson@linaro.org> wrote:
> If translation is disabled, the default memory type is Device, which
> requires alignment checking. This is more optimally done early via
> the MemOp given to the TCG memory operation.
>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> Reported-by: Idan Horowitz <idan.horowitz@gmail.com>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1204
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Hi Richard.
I noticed some tests I was running stopped booting with master.
(it's a fun and complex stack of QEMU + kvm on QEMU for vCPU Hotplug kernel
work,
but this is the host booting)
EDK2 build from upstream as of somepoint last week.
Bisects to this patch.
qemu-system-aarch64 -M virt,gic-version=3,virtualization=true -m
4g,maxmem=8G,slots=8 -cpu cortex-a76 -smp cpus=4,threads=2,clusters=2,sockets=1
\
-kernel Image \
-drive if=none,file=full.qcow2,format=qcow2,id=hd \
-device ioh3420,id=root_port1 -device virtio-blk-pci,drive=hd \
-netdev user,id=mynet,hostfwd=tcp::5555-:22 -device
virtio-net-pci,netdev=mynet,id=bob \
-nographic -no-reboot -append 'earlycon root=/dev/vda2 fsck.mode=skip
tp_printk' \
-monitor telnet:127.0.0.1:1235,server,nowait -bios QEMU_EFI.fd \
-object memory-backend-ram,size=4G,id=mem0 \
-numa node,nodeid=0,cpus=0-3,memdev=mem0
Symptoms: Nothing on console from edk2 which is built in debug mode so is
normally very noisy.
No sign of anything much happening at all :(
Jonathan
> ---
> target/arm/tcg/hflags.c | 34 ++++++++++++++++++++++++++++++++--
> 1 file changed, 32 insertions(+), 2 deletions(-)
>
> diff --git a/target/arm/tcg/hflags.c b/target/arm/tcg/hflags.c
> index 8e5d35d922..5da1b0fc1d 100644
> --- a/target/arm/tcg/hflags.c
> +++ b/target/arm/tcg/hflags.c
> @@ -26,6 +26,35 @@ static inline bool fgt_svc(CPUARMState *env, int el)
> FIELD_EX64(env->cp15.fgt_exec[FGTREG_HFGITR], HFGITR_EL2, SVC_EL1);
> }
>
> +/* Return true if memory alignment should be enforced. */
> +static bool aprofile_require_alignment(CPUARMState *env, int el, uint64_t
> sctlr)
> +{
> +#ifdef CONFIG_USER_ONLY
> + return false;
> +#else
> + /* Check the alignment enable bit. */
> + if (sctlr & SCTLR_A) {
> + return true;
> + }
> +
> + /*
> + * If translation is disabled, then the default memory type is
> + * Device(-nGnRnE) instead of Normal, which requires that alignment
> + * be enforced. Since this affects all ram, it is most efficient
> + * to handle this during translation.
> + */
> + if (sctlr & SCTLR_M) {
> + /* Translation enabled: memory type in PTE via MAIR_ELx. */
> + return false;
> + }
> + if (el < 2 && (arm_hcr_el2_eff(env) & (HCR_DC | HCR_VM))) {
> + /* Stage 2 translation enabled: memory type in PTE. */
> + return false;
> + }
> + return true;
> +#endif
> +}
> +
> static CPUARMTBFlags rebuild_hflags_common(CPUARMState *env, int fp_el,
> ARMMMUIdx mmu_idx,
> CPUARMTBFlags flags)
> @@ -121,8 +150,9 @@ static CPUARMTBFlags rebuild_hflags_a32(CPUARMState *env,
> int fp_el,
> {
> CPUARMTBFlags flags = {};
> int el = arm_current_el(env);
> + uint64_t sctlr = arm_sctlr(env, el);
>
> - if (arm_sctlr(env, el) & SCTLR_A) {
> + if (aprofile_require_alignment(env, el, sctlr)) {
> DP_TBFLAG_ANY(flags, ALIGN_MEM, 1);
> }
>
> @@ -223,7 +253,7 @@ static CPUARMTBFlags rebuild_hflags_a64(CPUARMState *env,
> int el, int fp_el,
>
> sctlr = regime_sctlr(env, stage1);
>
> - if (sctlr & SCTLR_A) {
> + if (aprofile_require_alignment(env, el, sctlr)) {
> DP_TBFLAG_ANY(flags, ALIGN_MEM, 1);
> }
>
- Re: [PATCH v3 5/6] target/arm: Do memory type alignment check when translation disabled,
Jonathan Cameron <=
- Re: [PATCH v3 5/6] target/arm: Do memory type alignment check when translation disabled, Richard Henderson, 2024/04/17
- Re: [PATCH v3 5/6] target/arm: Do memory type alignment check when translation disabled, Jonathan Cameron, 2024/04/18
- Re: [PATCH v3 5/6] target/arm: Do memory type alignment check when translation disabled, Jonathan Cameron, 2024/04/18
- Re: [edk2-devel] [PATCH v3 5/6] target/arm: Do memory type alignment check when translation disabled, Gerd Hoffmann, 2024/04/19
- Re: [edk2-devel] [PATCH v3 5/6] target/arm: Do memory type alignment check when translation disabled, Jonathan Cameron, 2024/04/19
- Re: [edk2-devel] [PATCH v3 5/6] target/arm: Do memory type alignment check when translation disabled, Ard Biesheuvel, 2024/04/19
- Re: [edk2-devel] [PATCH v3 5/6] target/arm: Do memory type alignment check when translation disabled, Ard Biesheuvel, 2024/04/19