KVM: arm64: Fix the value of the CPTR_EL2 RES1 bitmask for nVHE

Since the introduction of SME, bit 12 in CPTR_EL2 (nVHE) is TSM
for trapping SME, instead of RES1, as per ARM ARM DDI 0487K.a,
section D23.2.34.

Fix the value of CPTR_NVHE_EL2_RES1 to reflect that, and adjust
the code that relies on it accordingly.

Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20241216105057.579031-15-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>

Author: Fuad Tabba

arch/arm64/include/asm/kvm_arm.h

@@ -300,7 +300,7 @@
 #define CPTR_EL2_TSM	(1 << 12)
 #define CPTR_EL2_TFP	(1 << CPTR_EL2_TFP_SHIFT)
 #define CPTR_EL2_TZ	(1 << 8)
-#define CPTR_NVHE_EL2_RES1	0x000032ff /* known RES1 bits in CPTR_EL2 (nVHE) */
+#define CPTR_NVHE_EL2_RES1	(BIT(13) | BIT(9) | GENMASK(7, 0))
 #define CPTR_NVHE_EL2_RES0	(GENMASK(63, 32) |	\
 				 GENMASK(29, 21) |	\
 				 GENMASK(19, 14) |	\

arch/arm64/include/asm/kvm_emulate.h

@@ -640,8 +640,8 @@ static __always_inline void kvm_reset_cptr_el2(struct kvm_vcpu *vcpu)
 
 		if (vcpu_has_sve(vcpu) && guest_owns_fp_regs())
 			val |= CPTR_EL2_TZ;
-		if (cpus_have_final_cap(ARM64_SME))
-			val &= ~CPTR_EL2_TSM;
+		if (!cpus_have_final_cap(ARM64_SME))
+			val |= CPTR_EL2_TSM;
 	}
 
 	kvm_write_cptr_el2(val);