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authorWill Deacon <will.deacon@arm.com>2018-08-08 16:10:54 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2018-09-14 17:46:20 +0100
commit7c36447ae5a090729e7b129f24705bb231a07e0b (patch)
tree30a096c5533d645081b5a558d6c538c3a245ae32 /arch/arm64
parentarm64: ssbd: Add support for PSTATE.SSBS rather than trapping to EL3 (diff)
downloadlinux-dev-7c36447ae5a090729e7b129f24705bb231a07e0b.tar.xz
linux-dev-7c36447ae5a090729e7b129f24705bb231a07e0b.zip
KVM: arm64: Set SCTLR_EL2.DSSBS if SSBD is forcefully disabled and !vhe
When running without VHE, it is necessary to set SCTLR_EL2.DSSBS if SSBD has been forcefully disabled on the kernel command-line. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/include/asm/kvm_host.h11
-rw-r--r--arch/arm64/kvm/hyp/sysreg-sr.c11
2 files changed, 22 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index f26055f2306e..15501921fc75 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -389,6 +389,8 @@ struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);
DECLARE_PER_CPU(kvm_cpu_context_t, kvm_host_cpu_state);
+void __kvm_enable_ssbs(void);
+
static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr,
unsigned long hyp_stack_ptr,
unsigned long vector_ptr)
@@ -409,6 +411,15 @@ static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr,
*/
BUG_ON(!static_branch_likely(&arm64_const_caps_ready));
__kvm_call_hyp((void *)pgd_ptr, hyp_stack_ptr, vector_ptr, tpidr_el2);
+
+ /*
+ * Disabling SSBD on a non-VHE system requires us to enable SSBS
+ * at EL2.
+ */
+ if (!has_vhe() && this_cpu_has_cap(ARM64_SSBS) &&
+ arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) {
+ kvm_call_hyp(__kvm_enable_ssbs);
+ }
}
static inline bool kvm_arch_check_sve_has_vhe(void)
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
index 9ce223944983..76d016b446b2 100644
--- a/arch/arm64/kvm/hyp/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/sysreg-sr.c
@@ -288,3 +288,14 @@ void kvm_vcpu_put_sysregs(struct kvm_vcpu *vcpu)
vcpu->arch.sysregs_loaded_on_cpu = false;
}
+
+void __hyp_text __kvm_enable_ssbs(void)
+{
+ u64 tmp;
+
+ asm volatile(
+ "mrs %0, sctlr_el2\n"
+ "orr %0, %0, %1\n"
+ "msr sctlr_el2, %0"
+ : "=&r" (tmp) : "L" (SCTLR_ELx_DSSBS));
+}