From: Will Deacon will.deacon@arm.com
[ Upstream commit 7c36447ae5a090729e7b129f24705bb231a07e0b ]
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 Signed-off-by: Ard Biesheuvel ard.biesheuvel@linaro.org --- arch/arm64/include/asm/kvm_host.h | 11 +++++++++++ arch/arm64/kvm/hyp/sysreg-sr.c | 11 +++++++++++ 2 files changed, 22 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index b01ad3489bd8..f982c9d1d10b 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -356,6 +356,8 @@ struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr); void __kvm_set_tpidr_el2(u64 tpidr_el2); 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) @@ -380,6 +382,15 @@ static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr, - (u64)kvm_ksym_ref(kvm_host_cpu_state);
kvm_call_hyp(__kvm_set_tpidr_el2, 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 void kvm_arch_hardware_unsetup(void) {} diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c index e19d89cabf2a..3773311ffcd0 100644 --- a/arch/arm64/kvm/hyp/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/sysreg-sr.c @@ -188,3 +188,14 @@ void __hyp_text __kvm_set_tpidr_el2(u64 tpidr_el2) { asm("msr tpidr_el2, %0": : "r" (tpidr_el2)); } + +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)); +}