arm64: Rewrite Spectre-v4 mitigation code

Rewrite the Spectre-v4 mitigation handling code to follow the same
approach as that taken by Spectre-v2.

For now, report to KVM that the system is vulnerable (by forcing
'ssbd_state' to ARM64_SSBD_UNKNOWN), as this will be cleared up in
subsequent steps.

Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 1 insertions, 5 deletions

diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index 68e14152d6e9..c7b00120dc3e 100644
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -332,11 +332,7 @@ int swsusp_arch_suspend(void)
 		 * mitigation off behind our back, let's set the state
 		 * to what we expect it to be.
 		 */
-		switch (arm64_get_ssbd_state()) {
-		case ARM64_SSBD_FORCE_ENABLE:
-		case ARM64_SSBD_KERNEL:
-			arm64_set_ssbd_mitigation(true);
-		}
+		spectre_v4_enable_mitigation(NULL);
 	}
 
 	local_daif_restore(flags);