[PATCH v12 24/29] KVM: arm64: Expose SME to nested guests

[Mark Brown <broonie@kernel.org>]

With support for context switching SME state in place allow access to SME
in nested guests.

The SME floating point state is handled along with all the other floating
point state, SME specific floating point exceptions are directed into the
same handlers as other floating point exceptions with NV specific handling
for the vector lengths already in place.

TPIDR2_EL0 is context switched along with the other TPIDRs as part of the
main guest register context switch.

SME priority support is currently masked from all guests including nested
ones.

Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 arch/arm64/include/asm/kvm_nested.h | 2 ++
 arch/arm64/kvm/nested.c             | 3 +--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h
index cdf3e8422ea1..9df3cea39b09 100644
--- a/arch/arm64/include/asm/kvm_nested.h
+++ b/arch/arm64/include/asm/kvm_nested.h
@@ -42,6 +42,8 @@ static inline u64 translate_cptr_el2_to_cpacr_el1(u64 cptr_el2)
 		cpacr_el1 |= CPACR_EL1_FPEN;
 	if (!(cptr_el2 & CPTR_EL2_TZ))
 		cpacr_el1 |= CPACR_EL1_ZEN;
+	if (!(cptr_el2 & CPTR_EL2_TSM))
+		cpacr_el1 |= CPACR_EL1_SMEN;
 
 	cpacr_el1 |= cptr_el2 & (CPTR_EL2_TCPAC | CPTR_EL2_TAM);
 
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 50e25ab9b604..fb6087426f95 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -1630,14 +1630,13 @@ u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val)
 		break;
 
 	case SYS_ID_AA64PFR1_EL1:
-		/* Only support BTI, SSBS, CSV2_frac */
+		/* Only support BTI, SME, SSBS, CSV2_frac */
 		val &= ~(ID_AA64PFR1_EL1_PFAR		|
 			 ID_AA64PFR1_EL1_MTEX		|
 			 ID_AA64PFR1_EL1_THE		|
 			 ID_AA64PFR1_EL1_GCS		|
 			 ID_AA64PFR1_EL1_MTE_frac	|
 			 ID_AA64PFR1_EL1_NMI		|
-			 ID_AA64PFR1_EL1_SME		|
 			 ID_AA64PFR1_EL1_RES0		|
 			 ID_AA64PFR1_EL1_MPAM_frac	|
 			 ID_AA64PFR1_EL1_MTE);

-- 
2.47.3