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From: David Brazdil <dbrazdil@google.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
	Dennis Zhou <dennis@kernel.org>, Tejun Heo <tj@kernel.org>,
	Christoph Lameter <cl@linux.com>, Arnd Bergmann <arnd@arndb.de>
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
	kernel-team@google.com, kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH 5/9] kvm: arm64: Duplicate arm64_ssbd_callback_required for nVHE hyp
Date: Wed, 22 Jul 2020 17:44:20 +0100
Message-ID: <20200722164424.42225-6-dbrazdil@google.com> (raw)
In-Reply-To: <20200722164424.42225-1-dbrazdil@google.com>

Hyp keeps track of which cores require SSBD callback by accessing a
kernel-proper global variable. Create an nVHE symbol of the same name
and copy the value from kernel proper to nVHE at KVM init time.

Done in preparation for separating percpu memory owned by kernel
proper and nVHE.

Signed-off-by: David Brazdil <dbrazdil@google.com>
---
 arch/arm64/include/asm/kvm_mmu.h | 10 +++++++---
 arch/arm64/kernel/image-vars.h   |  1 -
 arch/arm64/kvm/arm.c             |  2 +-
 arch/arm64/kvm/hyp/nvhe/switch.c |  3 +++
 4 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 22157ded04ca..e9e5875274cb 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -529,23 +529,27 @@ static inline int kvm_map_vectors(void)
 
 #ifdef CONFIG_ARM64_SSBD
 DECLARE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);
+DECLARE_KVM_NVHE_PER_CPU(u64, arm64_ssbd_callback_required);
 
-static inline int hyp_map_aux_data(void)
+static inline int hyp_init_aux_data(void)
 {
 	int cpu, err;
 
 	for_each_possible_cpu(cpu) {
 		u64 *ptr;
 
-		ptr = per_cpu_ptr(&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_map_aux_data(void)
+static inline int hyp_init_aux_data(void)
 {
 	return 0;
 }
diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index 9e897c500237..034cf21e67ce 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -69,7 +69,6 @@ KVM_NVHE_ALIAS(kvm_patch_vector_branch);
 KVM_NVHE_ALIAS(kvm_update_va_mask);
 
 /* Global kernel state accessed by nVHE hyp code. */
-KVM_NVHE_ALIAS(arm64_ssbd_callback_required);
 KVM_NVHE_ALIAS(kvm_host_data);
 KVM_NVHE_ALIAS(kvm_vgic_global_state);
 
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 98f05bdac3c1..a53e87305fa0 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1547,7 +1547,7 @@ static int init_hyp_mode(void)
 		}
 	}
 
-	err = hyp_map_aux_data();
+	err = hyp_init_aux_data();
 	if (err)
 		kvm_err("Cannot map host auxiliary data: %d\n", err);
 
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index ddb602ffb022..8c2bd04df813 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -27,6 +27,9 @@
 #include <asm/processor.h>
 #include <asm/thread_info.h>
 
+/* Non-VHE copy of the kernel symbol. */
+DEFINE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);
+
 static void __activate_traps(struct kvm_vcpu *vcpu)
 {
 	u64 val;
-- 
2.27.0

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  parent reply index

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-22 16:44 [PATCH 0/9] Independent per-CPU data section for nVHE David Brazdil
2020-07-22 16:44 ` [PATCH 1/9] Macros to override naming of percpu symbols and sections David Brazdil
2020-07-22 16:44 ` [PATCH 2/9] kvm: arm64: Remove __hyp_this_cpu_read David Brazdil
2020-07-22 16:44 ` [PATCH 3/9] kvm: arm64: Remove hyp_adr/ldr_this_cpu David Brazdil
2020-07-22 16:44 ` [PATCH 4/9] kvm: arm64: Add helpers for accessing nVHE hyp per-cpu vars David Brazdil
2020-07-22 16:44 ` David Brazdil [this message]
2020-07-22 16:44 ` [PATCH 6/9] kvm: arm64: Create separate instances of kvm_host_data for VHE/nVHE David Brazdil
2020-07-22 16:44 ` [PATCH 7/9] kvm: arm64: Mark hyp stack pages reserved David Brazdil
2020-07-22 16:44 ` [PATCH 8/9] kvm: arm64: Set up hyp percpu data for nVHE David Brazdil
2020-07-22 16:44 ` [PATCH 9/9] kvm: arm64: Remove unnecessary hyp mappings David Brazdil

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