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authorJulien Thierry <[email protected]>2017-12-06 17:09:49 +0000
committerChristoffer Dall <[email protected]>2017-12-18 10:53:22 +0100
commitbfe766cf65fb65e68c4764f76158718560bdcee5 (patch)
treedbca7a94f09182a850f02f0d521c87b470eedfd8
parent50c4c4e268a2d7a3e58ebb698ac74da0de40ae36 (diff)
arm64: kvm: Prevent restoring stale PMSCR_EL1 for vcpu
When VHE is not present, KVM needs to save and restores PMSCR_EL1 when possible. If SPE is used by the host, value of PMSCR_EL1 cannot be saved for the guest. If the host starts using SPE between two save+restore on the same vcpu, restore will write the value of PMSCR_EL1 read during the first save. Make sure __debug_save_spe_nvhe clears the value of the saved PMSCR_EL1 when the guest cannot use SPE. Signed-off-by: Julien Thierry <[email protected]> Cc: Christoffer Dall <[email protected]> Cc: Marc Zyngier <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: <[email protected]> Reviewed-by: Will Deacon <[email protected]> Reviewed-by: Christoffer Dall <[email protected]> Signed-off-by: Christoffer Dall <[email protected]>
-rw-r--r--arch/arm64/kvm/hyp/debug-sr.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/debug-sr.c b/arch/arm64/kvm/hyp/debug-sr.c
index 321c9c05dd9e..f4363d40e2cd 100644
--- a/arch/arm64/kvm/hyp/debug-sr.c
+++ b/arch/arm64/kvm/hyp/debug-sr.c
@@ -74,6 +74,9 @@ static void __hyp_text __debug_save_spe_nvhe(u64 *pmscr_el1)
{
u64 reg;
+ /* Clear pmscr in case of early return */
+ *pmscr_el1 = 0;
+
/* SPE present on this CPU? */
if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1),
ID_AA64DFR0_PMSVER_SHIFT))