Re: [PATCH v3 05/15] arm64: kvm: Build hyp-entry.S separately for VHE/nVHE
flat view
From: David Brazdil <hidden>
Date: 2020-06-25 11:54:06
Also in:
kvmarm, 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
Possibly related (same subject, not in this thread)
- 2020-06-18 · Re: [PATCH v3 05/15] arm64: kvm: Build hyp-entry.S separately for VHE/nVHE · Marc Zyngier <maz@kernel.org>
- 2020-06-18 · [PATCH v3 05/15] arm64: kvm: Build hyp-entry.S separately for VHE/nVHE · David Brazdil <hidden>
Hey Marc,
I'd be happy with the (maybe temporary) magic approach. It helps reasoning about things, and makes the transition smoother. Yes, bugs could crop up there, but given the static nature of obtaining a symbol's address, I'm fairly confident we'll get it right. The same cannot be said about pointers though.
Ok, so this is what it would look like:
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 6a682d66a640..0d1b3b1946f0 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h@@ -59,13 +59,14 @@ #define DECLARE_KVM_HYP_SYM(sym) \ DECLARE_KVM_VHE_SYM(sym); \ DECLARE_KVM_NVHE_SYM(sym) +#define CHOOSE_HYP_SYM(sym) (has_vhe() ? sym : kvm_nvhe_sym(sym)) /* Translate a kernel address of @sym into its equivalent linear mapping */ -#define kvm_ksym_ref(sym) \ +#define kvm_ksym_ref(ptr) \ ({ \ - void *val = &sym; \ + void *val = (ptr); \ if (!is_kernel_in_hyp_mode()) \ - val = lm_alias(&sym); \ + val = lm_alias((ptr)); \ val; \ }) #define kvm_ksym_ref_nvhe(sym) kvm_ksym_ref(kvm_nvhe_sym(sym))
@@ -76,7 +77,14 @@ struct kvm_vcpu; extern char __kvm_hyp_init[]; extern char __kvm_hyp_init_end[]; -extern char __kvm_hyp_vector[]; +DECLARE_KVM_HYP_SYM(__kvm_hyp_vector); +#define __kvm_hyp_vector CHOOSE_HYP_SYM(__kvm_hyp_vector) + +#ifdef CONFIG_KVM_INDIRECT_VECTORS +DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs); +#define __bp_harden_hyp_vecs CHOOSE_HYP_SYM(__bp_harden_hyp_vecs) +extern atomic_t arm64_el2_vector_last_slot; +#endif extern void __kvm_flush_vm_context(void); extern void __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa);
Everything compiles and boots. Only existing code I had to change was:
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 90cb90561446..34b551385153 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c@@ -1285,7 +1285,7 @@ static void cpu_init_hyp_mode(void) * so that we can use adr_l to access per-cpu variables in EL2. */ tpidr_el2 = ((unsigned long)this_cpu_ptr(&kvm_host_data) - - (unsigned long)kvm_ksym_ref(kvm_host_data)); + (unsigned long)kvm_ksym_ref(&kvm_host_data)); pgd_ptr = kvm_mmu_get_httbr(); hyp_stack_ptr = __this_cpu_read(kvm_arm_hyp_stack_page) + PAGE_SIZE;
WDYT? Thanks, -David _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel