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>
This commit is contained in:
Will Deacon 2018-08-08 16:10:54 +01:00 committed by Catalin Marinas
parent 8f04e8e6e2
commit 7c36447ae5
2 changed files with 22 additions and 0 deletions

View File

@ -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)

View File

@ -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));
}