arm64: KVM: Add ARCH_WORKAROUND_2 support for guests
In order to offer ARCH_WORKAROUND_2 support to guests, we need
a bit of infrastructure.
Let's add a flag indicating whether or not the guest uses
SSBD mitigation. Depending on the state of this flag, allow
KVM to disable ARCH_WORKAROUND_2 before entering the guest,
and enable it when exiting it.
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index f74987b..fbe4ddd 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -456,6 +456,30 @@ static inline int kvm_map_vectors(void)
}
#endif
+#ifdef CONFIG_ARM64_SSBD
+DECLARE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);
+
+static inline int hyp_map_aux_data(void)
+{
+ int cpu, err;
+
+ for_each_possible_cpu(cpu) {
+ u64 *ptr;
+
+ ptr = per_cpu_ptr(&arm64_ssbd_callback_required, cpu);
+ err = create_hyp_mappings(ptr, ptr + 1, PAGE_HYP);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+#else
+static inline int hyp_map_aux_data(void)
+{
+ return 0;
+}
+#endif
+
#define kvm_phys_to_vttbr(addr) phys_to_ttbr(addr)
#endif /* __ASSEMBLY__ */