[PATCH v2 2/2] arm64/kvm: Fine grain _EL2 system registers list that affect nested virtualization

From: Miguel Luis
Date: Mon Sep 25 2023 - 12:22:47 EST


Some _EL1 registers got included in the _EL2 ranges, which are not
affected by NV. Remove them, fine grain the ranges to exclusively
include the _EL2 ones and fold SPSR/ELR _EL2 registers into the
existing range.

Signed-off-by: Miguel Luis <miguel.luis@xxxxxxxxxx>
---
arch/arm64/kvm/emulate-nested.c | 44 ++++++++++++++++++++++++++++-----
1 file changed, 38 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c
index 9ced1bf0c2b7..f6d0c87803f4 100644
--- a/arch/arm64/kvm/emulate-nested.c
+++ b/arch/arm64/kvm/emulate-nested.c
@@ -649,14 +649,46 @@ static const struct encoding_to_trap_config encoding_to_cgt[] __initconst = {
SR_TRAP(SYS_APGAKEYHI_EL1, CGT_HCR_APK),
/* All _EL2 registers */
SR_RANGE_TRAP(sys_reg(3, 4, 0, 0, 0),
- sys_reg(3, 4, 3, 15, 7), CGT_HCR_NV),
+ sys_reg(3, 4, 4, 0, 1), CGT_HCR_NV),
/* Skip the SP_EL1 encoding... */
- SR_TRAP(SYS_SPSR_EL2, CGT_HCR_NV),
- SR_TRAP(SYS_ELR_EL2, CGT_HCR_NV),
- SR_RANGE_TRAP(sys_reg(3, 4, 4, 1, 1),
- sys_reg(3, 4, 10, 15, 7), CGT_HCR_NV),
+ SR_RANGE_TRAP(sys_reg(3, 4, 4, 3, 0),
+ sys_reg(3, 4, 10, 6, 7), CGT_HCR_NV),
+ /*
+ * Note that the spec. describes a group of MEC registers
+ * whose access should not trap, therefore skip the following:
+ * MECID_A0_EL2, MECID_A1_EL2, MECID_P0_EL2,
+ * MECID_P1_EL2, MECIDR_EL2, VMECID_A_EL2,
+ * VMECID_P_EL2.
+ */
SR_RANGE_TRAP(sys_reg(3, 4, 12, 0, 0),
- sys_reg(3, 4, 14, 15, 7), CGT_HCR_NV),
+ sys_reg(3, 4, 12, 1, 1), CGT_HCR_NV),
+ /* ICH_AP0R<m>_EL2 */
+ SR_RANGE_TRAP(SYS_ICH_AP0R0_EL2,
+ SYS_ICH_AP0R3_EL2, CGT_HCR_NV),
+ /* ICH_AP1R<m>_EL2 */
+ SR_RANGE_TRAP(SYS_ICH_AP1R0_EL2,
+ SYS_ICH_AP1R3_EL2, CGT_HCR_NV),
+ SR_RANGE_TRAP(sys_reg(3, 4, 12, 9, 5),
+ sys_reg(3, 4, 12, 11, 7), CGT_HCR_NV),
+ /* ICH_LR<m>_EL2 */
+ SR_RANGE_TRAP(SYS_ICH_LR0_EL2,
+ SYS_ICH_LR7_EL2, CGT_HCR_NV),
+ SR_RANGE_TRAP(SYS_ICH_LR8_EL2,
+ SYS_ICH_LR15_EL2, CGT_HCR_NV),
+ SR_RANGE_TRAP(sys_reg(3, 4, 13, 0, 1),
+ sys_reg(3, 4, 13, 0, 7), CGT_HCR_NV),
+ /* AMEVCNTVOFF0<n>_EL2 */
+ SR_RANGE_TRAP(sys_reg(3, 4, 13, 8, 0),
+ sys_reg(3, 4, 13, 8, 7), CGT_HCR_NV),
+ SR_RANGE_TRAP(sys_reg(3, 4, 13, 9, 0),
+ sys_reg(3, 4, 13, 9, 7), CGT_HCR_NV),
+ /* AMEVCNTVOFF1<n>_EL2 */
+ SR_RANGE_TRAP(sys_reg(3, 4, 13, 10, 0),
+ sys_reg(3, 4, 13, 10, 7), CGT_HCR_NV),
+ SR_RANGE_TRAP(sys_reg(3, 4, 13, 11, 0),
+ sys_reg(3, 4, 13, 11, 7), CGT_HCR_NV),
+ SR_RANGE_TRAP(sys_reg(3, 4, 14, 0, 3),
+ sys_reg(3, 4, 14, 5, 2), CGT_HCR_NV),
/* All _EL02, _EL12 registers */
SR_RANGE_TRAP(sys_reg(3, 5, 0, 0, 0),
sys_reg(3, 5, 10, 15, 7), CGT_HCR_NV),
--
2.39.2