| Message ID | 20220209124135.69183-2-agraf@csgraf.de |
|---|---|
| State | New |
| Headers | show |
| Series | [v3,1/2] hvf: arm: Use macros for sysreg shift/masking | expand |
On Wed, 9 Feb 2022 at 12:41, Alexander Graf <agraf@csgraf.de> wrote: > > Recent Linux versions added support to read ID_AA64ISAR2_EL1. On M1, > those reads trap into QEMU which handles them as faults. > > However, AArch64 ID registers should always read as RES0. Let's > handle them accordingly. > > This fixes booting Linux 5.17 guests. > > Cc: qemu-stable@nongnu.org > Reported-by: Ivan Babrou <ivan@cloudflare.com> > Signed-off-by: Alexander Graf <agraf@csgraf.de> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> thanks -- PMM
diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c index 8d0447ab01..5ca7aa2dcd 100644 --- a/target/arm/hvf/hvf.c +++ b/target/arm/hvf/hvf.c @@ -754,6 +754,15 @@ static bool hvf_handle_psci_call(CPUState *cpu) return true; } +static bool is_id_sysreg(uint32_t reg) +{ + return SYSREG_OP0(reg) == 3 && + SYSREG_OP1(reg) == 0 && + SYSREG_CRN(reg) == 0 && + SYSREG_CRM(reg) >= 1 && + SYSREG_CRM(reg) < 8; +} + static int hvf_sysreg_read(CPUState *cpu, uint32_t reg, uint32_t rt) { ARMCPU *arm_cpu = ARM_CPU(cpu); @@ -806,6 +815,11 @@ static int hvf_sysreg_read(CPUState *cpu, uint32_t reg, uint32_t rt) /* Dummy register */ break; default: + if (is_id_sysreg(reg)) { + /* ID system registers read as RES0 */ + val = 0; + break; + } cpu_synchronize_state(cpu); trace_hvf_unhandled_sysreg_read(env->pc, reg, SYSREG_OP0(reg),
Recent Linux versions added support to read ID_AA64ISAR2_EL1. On M1, those reads trap into QEMU which handles them as faults. However, AArch64 ID registers should always read as RES0. Let's handle them accordingly. This fixes booting Linux 5.17 guests. Cc: qemu-stable@nongnu.org Reported-by: Ivan Babrou <ivan@cloudflare.com> Signed-off-by: Alexander Graf <agraf@csgraf.de> --- v1 -> v2: - Handle all ID registers instead of just ID_AA64ISAR2_EL1. v2 -> v3: - Use new sysreg parsing macros - Remove useless check for op2 --- target/arm/hvf/hvf.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)