[snip]
>>
>> static int exit_hyp_mode(void)
>> {
>> - phys_addr_t exit_phys_addr, exit_end_phys_addr;
>> + phys_addr_t exit_phys_addr;
>> int cpu;
>>
>> exit_phys_addr = virt_to_phys(__kvm_hyp_exit);
>> - exit_end_phys_addr = virt_to_phys(__kvm_hyp_exit_end);
>> BUG_ON(exit_phys_addr & 0x1f);
>>
>> /*
>> - * Create identity mapping for the exit code.
>> - */
>> - hyp_idmap_add(kvm_hyp_pgd_get(),
>> - (unsigned long)exit_phys_addr,
>> - (unsigned long)exit_end_phys_addr);
>> -
>> - /*
>> * Execute the exit code on each CPU.
>> *
>> * Note: The stack is not mapped yet, so don't do anything else than
>
> this exit code will now fail because we called hyp_idmap_teardown()
> above, right?
>
> so I guess we could not call the teardown() function, but then we may
> have a conflict if the physical RAM base happens to overlap with the
> kernel address for Hyp code?
>
> Seems like we will have to make the hyp_init_static_idmap exported to
> support this.
>
> I'm thinking otherwise maybe we want the generic code to only manage
> the idmap-Hyp page table and then let callers provide its own hyp_pgd
> to work on. But this requires being able to switch between the two
> which requires a reserved virtual address range mapped the same in
> both page tables right?
>
> Other suggestions? (drop KVM module support, sad???)
>
I applied with the following fixup to kvm-a15-v9-stage.
diff --git a/arch/arm/include/asm/idmap.h b/arch/arm/include/asm/idmap.h
index 61c034e..a1ab8d6 100644
--- a/arch/arm/include/asm/idmap.h
+++ b/arch/arm/include/asm/idmap.h
@@ -15,6 +15,7 @@ void setup_mm_for_reboot(void);
extern pgd_t *hyp_pgd;
void hyp_idmap_teardown(void);
+void hyp_idmap_setup(void);
#endif
#endif /* __ASM_IDMAP_H */
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index bcb512e..62cc23c 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -821,6 +821,13 @@ static int exit_hyp_mode(void)
phys_addr_t exit_phys_addr;
int cpu;
+ /*
+ * TODO: flush Hyp TLB in case idmap code overlaps.
+ * Note that we should do this in the monitor code when switching the
+ * HVBAR, but this is going away and should be rather done in the Hyp
+ * mode change of HVBAR.
+ */
+ hyp_idmap_setup();
exit_phys_addr = virt_to_phys(__kvm_hyp_exit);
BUG_ON(exit_phys_addr & 0x1f);
diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S
index 6f7ed62..4db26cb 100644
--- a/arch/arm/kvm/init.S
+++ b/arch/arm/kvm/init.S
@@ -139,6 +139,7 @@ __do_hyp_exit:
isb
mcr p15, 4, sp, c1, c0, 0 @ HSCR
+ mcr p15, 4, r0, c8, c7, 0 @ Flush Hyp TLB, r0 ignored
isb
eret
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index a244aee..cbd5793 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -69,6 +69,7 @@ void free_hyp_pmds(void)
pmd = pmd_offset(pud, addr);
free_ptes(pmd, addr);
pmd_free(NULL, pmd);
+ pud_clear(pud);
}
mutex_unlock(&kvm_hyp_pgd_mutex);
}
diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c
index 60557e3..7a944af 100644
--- a/arch/arm/mm/idmap.c
+++ b/arch/arm/mm/idmap.c
@@ -102,6 +102,7 @@ early_initcall(init_static_idmap);
#ifdef CONFIG_ARM_VIRT_EXT
pgd_t *hyp_pgd;
+EXPORT_SYMBOL_GPL(hyp_pgd);
static void hyp_idmap_del_pmd(pgd_t *pgd, unsigned long addr)
{
@@ -139,14 +140,20 @@ void hyp_idmap_teardown(void)
}
EXPORT_SYMBOL_GPL(hyp_idmap_teardown);
+void hyp_idmap_setup(void)
+{
+ identity_mapping_add(hyp_pgd, __hyp_idmap_text_start,
+ __hyp_idmap_text_end, PMD_SECT_AP1);
+}
+EXPORT_SYMBOL_GPL(hyp_idmap_setup);
+
static int __init hyp_init_static_idmap(void)
{
hyp_pgd = kzalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL);
if (!hyp_pgd)
return -ENOMEM;
- identity_mapping_add(hyp_pgd, __hyp_idmap_text_start,
- __hyp_idmap_text_end, PMD_SECT_AP1);
+ hyp_idmap_setup();
return 0;
}
-Christoffer
