On 26/04/13 11:45, Catalin Marinas wrote:
> On Fri, Apr 12, 2013 at 07:12:01PM +0100, Marc Zyngier wrote:
>> diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
>> index 2f12e40..3003321 100644
>> --- a/arch/arm/kvm/mmu.c
>> +++ b/arch/arm/kvm/mmu.c
> ...
>> -static int __create_hyp_mappings(void *from, void *to, unsigned long *pfn_base)
>> +static int __create_hyp_mappings(pgd_t *pgdp,
>> + unsigned long start, unsigned long end,
>> + unsigned long pfn, pgprot_t prot)
>> {
>> - unsigned long start = (unsigned long)from;
>> - unsigned long end = (unsigned long)to;
>> pgd_t *pgd;
>> pud_t *pud;
>> pmd_t *pmd;
>> @@ -209,21 +181,14 @@ static int __create_hyp_mappings(void *from, void *to, unsigned long *pfn_base)
>>
>> if (start >= end)
>> return -EINVAL;
>> - /* Check for a valid kernel memory mapping */
>> - if (!pfn_base && (!virt_addr_valid(from) || !virt_addr_valid(to - 1)))
>> - return -EINVAL;
>> - /* Check for a valid kernel IO mapping */
>> - if (pfn_base && (!is_vmalloc_addr(from) || !is_vmalloc_addr(to - 1)))
>> - return -EINVAL;
>>
>> mutex_lock(&kvm_hyp_pgd_mutex);
>> - for (addr = start; addr < end; addr = next) {
>> - unsigned long hyp_addr = KERN_TO_HYP(addr);
>> - pgd = hyp_pgd + pgd_index(hyp_addr);
>> - pud = pud_offset(pgd, hyp_addr);
>> + for (addr = start & PAGE_MASK; addr < end; addr = next) {
>> + pgd = pgdp + pgd_index(addr);
>> + pud = pud_offset(pgd, addr);
>>
>> if (pud_none_or_clear_bad(pud)) {
>> - pmd = pmd_alloc_one(NULL, hyp_addr);
>> + pmd = pmd_alloc_one(NULL, addr);
>> if (!pmd) {
>> kvm_err("Cannot allocate Hyp pmd\n");
>> err = -ENOMEM;
>> @@ -233,9 +198,10 @@ static int __create_hyp_mappings(void *from, void *to, unsigned long *pfn_base)
>> }
>>
>> next = pgd_addr_end(addr, end);
>> - err = create_hyp_pmd_mappings(pud, addr, next, pfn_base);
>> + err = create_hyp_pmd_mappings(pud, addr, next, pfn, prot);
>
> I would add another indirection function here like
> create_hyp_pud_mappings() if we are to share this code with arm64. If
> written correctly, the compiler should turn it into no-op. But here you
> just make the assumption that pgd/pud are the same.
Yes, it is a problem that is present across most of KVM/arm[64]. In
general, the code assumes that PUD is folded into PGD.
0> (it can be additional patch at some point if you already prepared these
> patches for upstream)
It is my intention to have an additional patch series that adds proper
PUD handling, so we could properly support 4 level page tables without
any other change.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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