Thread (10 messages) 10 messages, 1 author, 2020-07-22
DORMANTno replies
Revisions (4)
  1. v1 current
  2. v2 [diff vs current]
  3. v3 [diff vs current]
  4. v4 [diff vs current]

[PATCH 5/9] kvm: arm64: Duplicate arm64_ssbd_callback_required for nVHE hyp

From: David Brazdil <hidden>
Date: 2020-07-22 16:45:33
Also in: kvmarm, linux-arch, lkml
Subsystem: arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers: Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds

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 <redacted>
---
 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


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help