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From: marc.zyngier@arm.com (Marc Zyngier)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 3/4] KVM: arm/arm64: Remove unnecessary CMOs when creating HYP page tables
Date: Thu, 17 May 2018 11:35:47 +0100	[thread overview]
Message-ID: <20180517103548.5622-4-marc.zyngier@arm.com> (raw)
In-Reply-To: <20180517103548.5622-1-marc.zyngier@arm.com>

There is no need to perform cache maintenance operations when
creating the HYP page tables if we have the multiprocessing
extensions. ARMv7 mandates them with the virtualization support,
and ARMv8 just mandates them unconditionally.

Let's remove these operations.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/mmu.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index ba66bf7ae299..acbfea09578c 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -578,7 +578,6 @@ static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start,
 		pte = pte_offset_kernel(pmd, addr);
 		kvm_set_pte(pte, pfn_pte(pfn, prot));
 		get_page(virt_to_page(pte));
-		kvm_flush_dcache_to_poc(pte, sizeof(*pte));
 		pfn++;
 	} while (addr += PAGE_SIZE, addr != end);
 }
@@ -605,7 +604,6 @@ static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start,
 			}
 			pmd_populate_kernel(NULL, pmd, pte);
 			get_page(virt_to_page(pmd));
-			kvm_flush_dcache_to_poc(pmd, sizeof(*pmd));
 		}
 
 		next = pmd_addr_end(addr, end);
@@ -638,7 +636,6 @@ static int create_hyp_pud_mappings(pgd_t *pgd, unsigned long start,
 			}
 			pud_populate(NULL, pud, pmd);
 			get_page(virt_to_page(pud));
-			kvm_flush_dcache_to_poc(pud, sizeof(*pud));
 		}
 
 		next = pud_addr_end(addr, end);
@@ -675,7 +672,6 @@ static int __create_hyp_mappings(pgd_t *pgdp, unsigned long ptrs_per_pgd,
 			}
 			pgd_populate(NULL, pgd, pud);
 			get_page(virt_to_page(pgd));
-			kvm_flush_dcache_to_poc(pgd, sizeof(*pgd));
 		}
 
 		next = pgd_addr_end(addr, end);
@@ -685,6 +681,7 @@ static int __create_hyp_mappings(pgd_t *pgdp, unsigned long ptrs_per_pgd,
 		pfn += (next - addr) >> PAGE_SHIFT;
 	} while (addr = next, addr != end);
 out:
+	dsb(ishst);
 	mutex_unlock(&kvm_hyp_pgd_mutex);
 	return err;
 }
-- 
2.14.2

  parent reply	other threads:[~2018-05-17 10:35 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-17 10:35 [PATCH 0/4] KVM/arm64: Cache maintenance relaxations Marc Zyngier
2018-05-17 10:35 ` [PATCH 1/4] arm64: KVM: Add support for Stage-2 control of memory types and cacheability Marc Zyngier
2018-05-24 15:52   ` Catalin Marinas
2018-05-17 10:35 ` [PATCH 2/4] arm64: KVM: Avoid marking pages as XN in Stage-2 if CTR_EL0.DIC is set Marc Zyngier
2018-05-24 15:52   ` Catalin Marinas
2018-05-17 10:35 ` Marc Zyngier [this message]
2018-05-24 15:51   ` [PATCH 3/4] KVM: arm/arm64: Remove unnecessary CMOs when creating HYP page tables Catalin Marinas
2018-05-24 16:36     ` Marc Zyngier
2018-05-24 17:12   ` Mark Rutland
2018-05-25  8:23     ` Marc Zyngier
2018-05-17 10:35 ` [PATCH 4/4] arm64: KVM: Handle Set/Way CMOs as NOPs if FWB is present Marc Zyngier

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