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| author | Claudio Imbrenda <imbrenda@linux.ibm.com> | 2022-06-28 15:56:11 +0200 |
|---|---|---|
| committer | Janosch Frank <frankja@linux.ibm.com> | 2022-07-19 14:06:56 +0200 |
| commit | 9bf811dae443794594615625577277852edc181b (patch) | |
| tree | 1110f92cd7638f5c876a1d1c873ae0051a5fae6d /arch/s390 | |
| parent | KVM: s390: pv: add mmu_notifier (diff) | |
| download | linux-9bf811dae443794594615625577277852edc181b.tar.xz linux-9bf811dae443794594615625577277852edc181b.zip | |
s390/mm: KVM: pv: when tearing down, try to destroy protected pages
When ptep_get_and_clear_full is called for a mm teardown, we will now
attempt to destroy the secure pages. This will be faster than export.
In case it was not a teardown, or if for some reason the destroy page
UVC failed, we try with an export page, like before.
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
Link: https://lore.kernel.org/r/20220628135619.32410-11-imbrenda@linux.ibm.com
Message-Id: <20220628135619.32410-11-imbrenda@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/include/asm/pgtable.h | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index f16403ba81ec..cf81acf3879c 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -1182,9 +1182,22 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, } else { res = ptep_xchg_lazy(mm, addr, ptep, __pte(_PAGE_INVALID)); } - /* At this point the reference through the mapping is still present */ - if (mm_is_protected(mm) && pte_present(res)) - uv_convert_owned_from_secure(pte_val(res) & PAGE_MASK); + /* Nothing to do */ + if (!mm_is_protected(mm) || !pte_present(res)) + return res; + /* + * At this point the reference through the mapping is still present. + * The notifier should have destroyed all protected vCPUs at this + * point, so the destroy should be successful. + */ + if (full && !uv_destroy_owned_page(pte_val(res) & PAGE_MASK)) + return res; + /* + * If something went wrong and the page could not be destroyed, or + * if this is not a mm teardown, the slower export is used as + * fallback instead. + */ + uv_convert_owned_from_secure(pte_val(res) & PAGE_MASK); return res; } |