Merge tag 'kvmarm-fixes-6.16-5' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.16, take #

- Remove the last leftovers from the ill-fated FPSIMD host state
  mapping at EL2 stage-1

- Fix unexpected advertisement to the guest of unimplemented S2 base
  granule sizes

Author: bonzini

arch/arm64/include/asm/kvm_host.h

@@ -1480,7 +1480,6 @@ int kvm_vm_ioctl_get_reg_writable_masks(struct kvm *kvm,
 					struct reg_mask_range *range);
 
 /* Guest/host FPSIMD coordination helpers */
-int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu);

arch/arm64/kvm/arm.c

@@ -825,10 +825,6 @@ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
 	if (!kvm_arm_vcpu_is_finalized(vcpu))
 		return -EPERM;
 
-	ret = kvm_arch_vcpu_run_map_fp(vcpu);
-	if (ret)
-		return ret;
-
 	if (likely(vcpu_has_run_once(vcpu)))
 		return 0;
 

arch/arm64/kvm/fpsimd.c

@@ -14,32 +14,6 @@
 #include <asm/kvm_mmu.h>
 #include <asm/sysreg.h>
 
-/*
- * Called on entry to KVM_RUN unless this vcpu previously ran at least
- * once and the most recent prior KVM_RUN for this vcpu was called from
- * the same task as current (highly likely).
- *
- * This is guaranteed to execute before kvm_arch_vcpu_load_fp(vcpu),
- * such that on entering hyp the relevant parts of current are already
- * mapped.
- */
-int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu)
-{
-	struct user_fpsimd_state *fpsimd = &current->thread.uw.fpsimd_state;
-	int ret;
-
-	/* pKVM has its own tracking of the host fpsimd state. */
-	if (is_protected_kvm_enabled())
-		return 0;
-
-	/* Make sure the host task fpsimd state is visible to hyp: */
-	ret = kvm_share_hyp(fpsimd, fpsimd + 1);
-	if (ret)
-		return ret;
-
-	return 0;
-}
-
 /*
  * Prepare vcpu for saving the host's FPSIMD state and loading the guest's.
  * The actual loading is done by the FPSIMD access trap taken to hyp.

arch/arm64/kvm/nested.c

@@ -1402,6 +1402,21 @@ static void kvm_map_l1_vncr(struct kvm_vcpu *vcpu)
 	}
 }
 
+#define has_tgran_2(__r, __sz)						\
+	({								\
+		u64 _s1, _s2, _mmfr0 = __r;				\
+									\
+		_s2 = SYS_FIELD_GET(ID_AA64MMFR0_EL1,			\
+				    TGRAN##__sz##_2, _mmfr0);		\
+									\
+		_s1 = SYS_FIELD_GET(ID_AA64MMFR0_EL1,			\
+				    TGRAN##__sz, _mmfr0);		\
+									\
+		((_s2 != ID_AA64MMFR0_EL1_TGRAN##__sz##_2_NI &&		\
+		  _s2 != ID_AA64MMFR0_EL1_TGRAN##__sz##_2_TGRAN##__sz) || \
+		 (_s2 == ID_AA64MMFR0_EL1_TGRAN##__sz##_2_TGRAN##__sz && \
+		  _s1 != ID_AA64MMFR0_EL1_TGRAN##__sz##_NI));		\
+	})
 /*
  * Our emulated CPU doesn't support all the possible features. For the
  * sake of simplicity (and probably mental sanity), wipe out a number
@@ -1411,6 +1426,8 @@ static void kvm_map_l1_vncr(struct kvm_vcpu *vcpu)
  */
 u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val)
 {
+	u64 orig_val = val;
+
 	switch (reg) {
 	case SYS_ID_AA64ISAR0_EL1:
 		/* Support everything but TME */
@@ -1480,13 +1497,16 @@ u64 limit_nv_id_reg(struct kvm *kvm, u32 reg, u64 val)
 		 */
 		switch (PAGE_SIZE) {
 		case SZ_4K:
-			val |= SYS_FIELD_PREP_ENUM(ID_AA64MMFR0_EL1, TGRAN4_2, IMP);
+			if (has_tgran_2(orig_val, 4))
+				val |= SYS_FIELD_PREP_ENUM(ID_AA64MMFR0_EL1, TGRAN4_2, IMP);
 			fallthrough;
 		case SZ_16K:
-			val |= SYS_FIELD_PREP_ENUM(ID_AA64MMFR0_EL1, TGRAN16_2, IMP);
+			if (has_tgran_2(orig_val, 16))
+				val |= SYS_FIELD_PREP_ENUM(ID_AA64MMFR0_EL1, TGRAN16_2, IMP);
 			fallthrough;
 		case SZ_64K:
-			val |= SYS_FIELD_PREP_ENUM(ID_AA64MMFR0_EL1, TGRAN64_2, IMP);
+			if (has_tgran_2(orig_val, 64))
+				val |= SYS_FIELD_PREP_ENUM(ID_AA64MMFR0_EL1, TGRAN64_2, IMP);
 			break;
 		}