linux-kernel - [PATCH v3 11/11] kvm: arm64: Remove unnecessary hyp mappings

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Message-Id: <20200916173439.32265-12-dbrazdil@google.com>
Date:   Wed, 16 Sep 2020 18:34:39 +0100
From:   David Brazdil <dbrazdil@...gle.com>
To:     kvmarm@...ts.cs.columbia.edu
Cc:     Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>, Marc Zyngier <maz@...nel.org>,
        James Morse <james.morse@....com>,
        Julien Thierry <julien.thierry.kdev@...il.com>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Dennis Zhou <dennis@...nel.org>, Tejun Heo <tj@...nel.org>,
        Christoph Lameter <cl@...ux.com>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        kernel-team@...roid.com, David Brazdil <dbrazdil@...gle.com>,
        Andrew Scull <ascull@...gle.com>
Subject: [PATCH v3 11/11] kvm: arm64: Remove unnecessary hyp mappings

With all nVHE per-CPU variables being part of the hyp per-CPU region,
mapping them individual is not necessary any longer. They are mapped to hyp
as part of the overall per-CPU region.

Acked-by: Andrew Scull<ascull@...gle.com>
Signed-off-by: David Brazdil <dbrazdil@...gle.com>
---
 arch/arm64/include/asm/kvm_mmu.h | 19 +++++--------------
 arch/arm64/kvm/arm.c             | 17 +----------------
 2 files changed, 6 insertions(+), 30 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 9db93da35606..7d1581bc8b97 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -531,28 +531,19 @@ static inline int kvm_map_vectors(void)
 DECLARE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);
 DECLARE_KVM_NVHE_PER_CPU(u64, arm64_ssbd_callback_required);
 
-static inline int hyp_init_aux_data(void)
+static inline void hyp_init_aux_data(void)
 {
-	int cpu, err;
+	int cpu;
 
+	/* Copy arm64_ssbd_callback_required values from kernel to hyp. */
 	for_each_possible_cpu(cpu) {
-		u64 *ptr;
+		u64 *ptr = per_cpu_ptr_nvhe(arm64_ssbd_callback_required, cpu);
 
-		ptr = per_cpu_ptr_nvhe(arm64_ssbd_callback_required, cpu);
-		err = create_hyp_mappings(ptr, ptr + 1, PAGE_HYP);
-		if (err)
-			return err;
-
-		/* Copy value from kernel to hyp. */
 		*ptr = per_cpu(arm64_ssbd_callback_required, cpu);
 	}
-	return 0;
 }
 #else
-static inline int hyp_init_aux_data(void)
-{
-	return 0;
-}
+static inline void hyp_init_aux_data(void) {}
 #endif
 
 #define kvm_phys_to_vttbr(addr)		phys_to_ttbr(addr)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 8293319a32e7..4483b6aca5d7 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1634,22 +1634,7 @@ static int init_hyp_mode(void)
 		}
 	}
 
-	for_each_possible_cpu(cpu) {
-		kvm_host_data_t *cpu_data;
-
-		cpu_data = per_cpu_ptr_hyp(kvm_host_data, cpu);
-		err = create_hyp_mappings(cpu_data, cpu_data + 1, PAGE_HYP);
-
-		if (err) {
-			kvm_err("Cannot map host CPU state: %d\n", err);
-			goto out_err;
-		}
-	}
-
-	err = hyp_init_aux_data();
-	if (err)
-		kvm_err("Cannot map host auxiliary data: %d\n", err);
-
+	hyp_init_aux_data();
 	return 0;
 
 out_err:
-- 
2.28.0.618.gf4bc123cb7-goog