[PATCH 3/5] KVM: arm64: Refine _EL2 system register list that require trap reinjection

[Marc Zyngier]

From: Miguel Luis <miguel.luis at oracle.com>

Implement a fine grained approach in the _EL2 sysreg range instead of
the current wide cast trap. This ensures that we don't mistakenly
inject the wrong exception into the guest.

Fixes: d0fc0a2519a6 ("KVM: arm64: nv: Add trap forwarding for HCR_EL2")
Reviewed-by: Eric Auger <eric.auger at redhat.com>
Signed-off-by: Miguel Luis <miguel.luis at oracle.com>
[maz: commit message massaging, dropped secure and AArch32 registers
      from the list]
Signed-off-by: Marc Zyngier <maz at kernel.org>
Link: https://lore.kernel.org/r/20231016111743.30331-4-miguel.luis@oracle.com
---
 arch/arm64/kvm/emulate-nested.c | 77 ++++++++++++++++++++++++++++++---
 1 file changed, 71 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c
index ee902ff2a50f..06185216a297 100644
--- a/arch/arm64/kvm/emulate-nested.c
+++ b/arch/arm64/kvm/emulate-nested.c
@@ -648,15 +648,80 @@ static const struct encoding_to_trap_config encoding_to_cgt[] __initconst = {
 	SR_TRAP(SYS_APGAKEYLO_EL1,	CGT_HCR_APK),
 	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),
+	SR_TRAP(SYS_BRBCR_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_VPIDR_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_VMPIDR_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_SCTLR_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_ACTLR_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_SCTLR2_EL2,		CGT_HCR_NV),
+	SR_RANGE_TRAP(SYS_HCR_EL2,
+		      SYS_HCRX_EL2,	CGT_HCR_NV),
+	SR_TRAP(SYS_SMPRIMAP_EL2,	CGT_HCR_NV),
+	SR_TRAP(SYS_SMCR_EL2,		CGT_HCR_NV),
+	SR_RANGE_TRAP(SYS_TTBR0_EL2,
+		      SYS_TCR2_EL2,	CGT_HCR_NV),
+	SR_TRAP(SYS_VTTBR_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_VTCR_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_VNCR_EL2,		CGT_HCR_NV),
+	SR_RANGE_TRAP(SYS_HDFGRTR_EL2,
+		      SYS_HAFGRTR_EL2,	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, 12, 0, 0),
-		      sys_reg(3, 4, 14, 15, 7), CGT_HCR_NV),
+	/* Skip SPSR_irq, SPSR_abt, SPSR_und, SPSR_fiq */
+	SR_TRAP(SYS_AFSR0_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_AFSR1_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_ESR_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_VSESR_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_TFSR_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_FAR_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_HPFAR_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_PMSCR_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_MAIR_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_AMAIR_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_MPAMHCR_EL2,	CGT_HCR_NV),
+	SR_TRAP(SYS_MPAMVPMV_EL2,	CGT_HCR_NV),
+	SR_TRAP(SYS_MPAM2_EL2,		CGT_HCR_NV),
+	SR_RANGE_TRAP(SYS_MPAMVPM0_EL2,
+		      SYS_MPAMVPM7_EL2,	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_VBAR_EL2,
+		      SYS_RMR_EL2,	CGT_HCR_NV),
+	SR_TRAP(SYS_VDISR_EL2,		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_TRAP(SYS_ICC_SRE_EL2,	CGT_HCR_NV),
+	SR_RANGE_TRAP(SYS_ICH_HCR_EL2,
+		      SYS_ICH_EISR_EL2,	CGT_HCR_NV),
+	SR_TRAP(SYS_ICH_ELRSR_EL2,	CGT_HCR_NV),
+	SR_TRAP(SYS_ICH_VMCR_EL2,	CGT_HCR_NV),
+	/* ICH_LR<m>_EL2 */
+	SR_RANGE_TRAP(SYS_ICH_LR0_EL2,
+		      SYS_ICH_LR15_EL2, CGT_HCR_NV),
+	SR_TRAP(SYS_CONTEXTIDR_EL2,	CGT_HCR_NV),
+	SR_TRAP(SYS_TPIDR_EL2,		CGT_HCR_NV),
+	SR_TRAP(SYS_SCXTNUM_EL2,	CGT_HCR_NV),
+	/* AMEVCNTVOFF0<n>_EL2, AMEVCNTVOFF1<n>_EL2  */
+	SR_RANGE_TRAP(SYS_AMEVCNTVOFF0n_EL2(0),
+		      SYS_AMEVCNTVOFF1n_EL2(15), CGT_HCR_NV),
+	/* CNT*_EL2 */
+	SR_TRAP(SYS_CNTVOFF_EL2,	CGT_HCR_NV),
+	SR_TRAP(SYS_CNTPOFF_EL2,	CGT_HCR_NV),
+	SR_TRAP(SYS_CNTHCTL_EL2,	CGT_HCR_NV),
+	SR_RANGE_TRAP(SYS_CNTHP_TVAL_EL2,
+		      SYS_CNTHP_CVAL_EL2, CGT_HCR_NV),
+	SR_RANGE_TRAP(SYS_CNTHV_TVAL_EL2,
+		      SYS_CNTHV_CVAL_EL2, 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