On 17/01/2020 14:56, Boris Ostrovsky wrote:
>
>
> On 1/17/20 7:58 AM, Sergey Dyasli wrote:
>> --- a/arch/x86/mm/kasan_init_64.c
>> +++ b/arch/x86/mm/kasan_init_64.c
>> @@ -13,6 +13,9 @@
>> #include <linux/sched/task.h>
>> #include <linux/vmalloc.h>
>> +#include <xen/xen.h>
>> +#include <xen/xen-ops.h>
>> +
>> #include <asm/e820/types.h>
>> #include <asm/pgalloc.h>
>> #include <asm/tlbflush.h>
>> @@ -332,6 +335,11 @@ void __init kasan_early_init(void)
>> for (i = 0; pgtable_l5_enabled() && i < PTRS_PER_P4D; i++)
>> kasan_early_shadow_p4d[i] = __p4d(p4d_val);
>> + if (xen_pv_domain()) {
>> + pgd_t *pv_top_pgt = xen_pv_kasan_early_init();
>> + kasan_map_early_shadow(pv_top_pgt);
>> + }
>> +
>
>
> I'd suggest replacing this with xen_kasan_early_init() and doing everything, including PV check, there. This way non-Xen code won't need to be aware of Xen-specific details such as guest types.
This would require exporting kasan_map_early_shadow() via kasan.h.
I'm fine with either approach.
>> kasan_map_early_shadow(early_top_pgt);
>> kasan_map_early_shadow(init_top_pgt);
>> }
>> @@ -369,6 +377,8 @@ void __init kasan_init(void)
>> __pgd(__pa(tmp_p4d_table) | _KERNPG_TABLE));
>> }
>> + xen_pv_kasan_pin_pgd(early_top_pgt);
>> +
>
> And drop "_pv" here (and below) for the same reason.
This is a reasonable suggestion.
>> load_cr3(early_top_pgt);
>> __flush_tlb_all();
>> @@ -433,6 +443,8 @@ void __init kasan_init(void)
>> load_cr3(init_top_pgt);
>> __flush_tlb_all();
>> + xen_pv_kasan_unpin_pgd(early_top_pgt);
>> +
>>
--
Thanks,
Sergey
