On 01/12/15 01:51, Shannon Zhao wrote:
> Hi Marc,
> 
> On 2015/12/1 1:56, Marc Zyngier wrote:
>> Same remark here as the one I made earlier. I'm pretty sure we don't
>> call any CP15 reset because they are all shared with their 64bit
>> counterparts. The same thing goes for the whole series.
> Ok, I see. But within the 64bit reset function, it needs to update the
> 32bit register value, right? Since when accessing these 32bit registers,
> it uses the offset c9_PMXXXX.

It shouldn't,  because the 64bit and 32bit share the same storage. From
your own patch:

+/* Performance Monitors*/
+#define c9_PMCR                (PMCR_EL0 * 2)
+#define c9_PMOVSSET    (PMOVSSET_EL0 * 2)
+#define c9_PMOVSCLR    (PMOVSCLR_EL0 * 2)
+#define c9_PMCCNTR     (PMCCNTR_EL0 * 2)
+#define c9_PMSELR      (PMSELR_EL0 * 2)
+#define c9_PMCEID0     (PMCEID0_EL0 * 2)
+#define c9_PMCEID1     (PMCEID1_EL0 * 2)
+#define c9_PMXEVCNTR   (PMXEVCNTR_EL0 * 2)
+#define c9_PMXEVTYPER  (PMXEVTYPER_EL0 * 2)
+#define c9_PMCNTENSET  (PMCNTENSET_EL0 * 2)
+#define c9_PMCNTENCLR  (PMCNTENCLR_EL0 * 2)
+#define c9_PMINTENSET  (PMINTENSET_EL1 * 2)
+#define c9_PMINTENCLR  (PMINTENCLR_EL1 * 2)
+#define c9_PMUSERENR   (PMUSERENR_EL0 * 2)
+#define c9_PMSWINC     (PMSWINC_EL0 * 2)

These are indexes in the copro array:

struct kvm_cpu_context {
        struct kvm_regs gp_regs;
        union {
                u64 sys_regs[NR_SYS_REGS];
                u32 copro[NR_COPRO_REGS];
        };
};

which is in a union with the sys_reg array. So anything that affects one
affects the other because:
- there is only one state in the physical CPU, no matter which mode
you're in,
- the guest EL1 is either 32bit or 64bit, and never changes over time.

Hope this helps,

        M.
-- 
Jazz is not dead. It just smells funny...
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to