From 21ad8c1c4fca0ffc5538fe7a0db9d01c6fcc67da Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 24 Oct 2023 10:15:19 +0200 Subject: s390/cmma: fix detection of DAT pages [ Upstream commit 44d93045247661acbd50b1629e62f415f2747577 ] If the cmma no-dat feature is available the kernel page tables are walked to identify and mark all pages which are used for address translation (all region, segment, and page tables). In a subsequent loop all other pages are marked as "no-dat" pages with the ESSA instruction. This information is visible to the hypervisor, so that the hypervisor can optimize purging of guest TLB entries. The initial loop however is incorrect: only the first three of the four pages which belong to segment and region tables will be marked as being used for DAT. The last page is incorrectly marked as no-dat. This can result in incorrect guest TLB flushes. Fix this by simply marking all four pages. Cc: Reviewed-by: Claudio Imbrenda Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin --- arch/s390/mm/page-states.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/s390/mm/page-states.c b/arch/s390/mm/page-states.c index 10d81deef330..bef7e07da98e 100644 --- a/arch/s390/mm/page-states.c +++ b/arch/s390/mm/page-states.c @@ -131,7 +131,7 @@ static void mark_kernel_pud(p4d_t *p4d, unsigned long addr, unsigned long end) continue; if (!pud_folded(*pud)) { page = phys_to_page(pud_val(*pud)); - for (i = 0; i < 3; i++) + for (i = 0; i < 4; i++) set_bit(PG_arch_1, &page[i].flags); } mark_kernel_pmd(pud, addr, next); @@ -152,7 +152,7 @@ static void mark_kernel_p4d(pgd_t *pgd, unsigned long addr, unsigned long end) continue; if (!p4d_folded(*p4d)) { page = phys_to_page(p4d_val(*p4d)); - for (i = 0; i < 3; i++) + for (i = 0; i < 4; i++) set_bit(PG_arch_1, &page[i].flags); } mark_kernel_pud(p4d, addr, next); @@ -174,7 +174,7 @@ static void mark_kernel_pgd(void) continue; if (!pgd_folded(*pgd)) { page = phys_to_page(pgd_val(*pgd)); - for (i = 0; i < 3; i++) + for (i = 0; i < 4; i++) set_bit(PG_arch_1, &page[i].flags); } mark_kernel_p4d(pgd, addr, next); -- cgit v1.2.3