Merge tag 'kvmarm-fixes-7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 7.1, take #2

- Add the pKVM side of the workaround for ARM's erratum 4193714, provided
  that the EL3 firmware does its part of the job. KVM will refuse to
  initialise otherwise.

- Correctly handle 52bit VAs for guest EL2 stage-1 translations when
  running under NV with E2H==0.

- Correctly deal with permission faults in guest_memfd memslots.

- Fix the steal-time selftest after the infrastructure was reworked.

- Make sure the host cannot pass a non-sensical clock update to the
  EL2 tracing infrastructure.

- Appoint Steffen Eiden as a reviewer in anticipation of the KVM/s390
  ability to run arm64 guests, which will inevitably lead to arm64
  code being directly used on s390.

- Make sure that EL2 is configured with both exception entry and exit
  being Context Synchronization Events.

- Handle the current vcpu being NULL on EL2 panic.

- Fix the selftest_vcpu memcache being empty at the point of donation or
  sharing.

- Check that the memcache has enough capacity before engaging on the
  share/donate path.

- Fix __deactivate_fgt() to use its parameter rather than a variable
  in the macro context.

MAINTAINERS

@@ -14052,6 +14052,7 @@ KERNEL VIRTUAL MACHINE FOR ARM64 (KVM/arm64)
 M:	Marc Zyngier <maz@kernel.org>
 M:	Oliver Upton <oupton@kernel.org>
 R:	Joey Gouly <joey.gouly@arm.com>
+R:	Steffen Eiden <seiden@linux.ibm.com>
 R:	Suzuki K Poulose <suzuki.poulose@arm.com>
 R:	Zenghui Yu <yuzenghui@huawei.com>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)

arch/arm64/include/asm/kvm_nested.h

@@ -23,6 +23,7 @@ static inline u64 tcr_el2_ps_to_tcr_el1_ips(u64 tcr_el2)
 static inline u64 translate_tcr_el2_to_tcr_el1(u64 tcr)
 {
 	return TCR_EPD1_MASK |				/* disable TTBR1_EL1 */
+	       ((tcr & TCR_EL2_DS) ? TCR_DS : 0) |
 	       ((tcr & TCR_EL2_TBI) ? TCR_TBI0 : 0) |
 	       tcr_el2_ps_to_tcr_el1_ips(tcr) |
 	       (tcr & TCR_EL2_TG0_MASK) |

arch/arm64/include/asm/sysreg.h

@@ -844,7 +844,7 @@
 #define INIT_SCTLR_EL2_MMU_ON						\
 	(SCTLR_ELx_M  | SCTLR_ELx_C | SCTLR_ELx_SA | SCTLR_ELx_I |	\
 	 SCTLR_ELx_IESB | SCTLR_ELx_WXN | ENDIAN_SET_EL2 |		\
-	 SCTLR_ELx_ITFSB | SCTLR_EL2_RES1)
+	 SCTLR_ELx_ITFSB | SCTLR_ELx_EIS | SCTLR_ELx_EOS | SCTLR_EL2_RES1)
 
 #define INIT_SCTLR_EL2_MMU_OFF \
 	(SCTLR_EL2_RES1 | ENDIAN_SET_EL2)

arch/arm64/kvm/arm.c

@@ -4,6 +4,7 @@
  * Author: Christoffer Dall <c.dall@virtualopensystems.com>
  */
 
+#include <linux/arm-smccc.h>
 #include <linux/bug.h>
 #include <linux/cpu_pm.h>
 #include <linux/errno.h>
@@ -2638,6 +2639,22 @@ static int init_pkvm_host_sve_state(void)
 	return 0;
 }
 
+static int pkvm_check_sme_dvmsync_fw_call(void)
+{
+	struct arm_smccc_res res;
+
+	if (!cpus_have_final_cap(ARM64_WORKAROUND_4193714))
+		return 0;
+
+	arm_smccc_1_1_smc(ARM_SMCCC_CPU_WORKAROUND_4193714, &res);
+	if (res.a0) {
+		kvm_err("pKVM requires firmware support for C1-Pro erratum 4193714\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
 /*
  * Finalizes the initialization of hyp mode, once everything else is initialized
  * and the initialziation process cannot fail.
@@ -2838,6 +2855,10 @@ static int __init init_hyp_mode(void)
 		if (err)
 			goto out_err;
 
+		err = pkvm_check_sme_dvmsync_fw_call();
+		if (err)
+			goto out_err;
+
 		err = kvm_hyp_init_protection(hyp_va_bits);
 		if (err) {
 			kvm_err("Failed to init hyp memory protection\n");

arch/arm64/kvm/hyp/include/hyp/switch.h

@@ -245,7 +245,7 @@ static inline void __activate_traps_ich_hfgxtr(struct kvm_vcpu *vcpu)
 	__activate_fgt(hctxt, vcpu, ICH_HFGITR_EL2);
 }
 
-#define __deactivate_fgt(htcxt, vcpu, reg)				\
+#define __deactivate_fgt(hctxt, vcpu, reg)				\
 	do {								\
 		write_sysreg_s(ctxt_sys_reg(hctxt, reg),		\
 			       SYS_ ## reg);				\

arch/arm64/kvm/hyp/nvhe/clock.c

@@ -35,6 +35,9 @@ void trace_clock_update(u32 mult, u32 shift, u64 epoch_ns, u64 epoch_cyc)
 	struct clock_data *clock = &trace_clock_data;
 	u64 bank = clock->cur ^ 1;
 
+	if (!mult || shift >= 64)
+		return;
+
 	clock->data[bank].mult			= mult;
 	clock->data[bank].shift			= shift;
 	clock->data[bank].epoch_ns		= epoch_ns;

arch/arm64/kvm/hyp/nvhe/mem_protect.c

@@ -5,6 +5,7 @@
  */
 
 #include <linux/kvm_host.h>
+
 #include <asm/kvm_emulate.h>
 #include <asm/kvm_hyp.h>
 #include <asm/kvm_mmu.h>
@@ -14,6 +15,7 @@
 
 #include <hyp/fault.h>
 
+#include <nvhe/arm-smccc.h>
 #include <nvhe/gfp.h>
 #include <nvhe/memory.h>
 #include <nvhe/mem_protect.h>
@@ -29,6 +31,19 @@ static struct hyp_pool host_s2_pool;
 static DEFINE_PER_CPU(struct pkvm_hyp_vm *, __current_vm);
 #define current_vm (*this_cpu_ptr(&__current_vm))
 
+static void pkvm_sme_dvmsync_fw_call(void)
+{
+	if (alternative_has_cap_unlikely(ARM64_WORKAROUND_4193714)) {
+		struct arm_smccc_res res;
+
+		/*
+		 * Ignore the return value. Probing for the workaround
+		 * availability took place in init_hyp_mode().
+		 */
+		hyp_smccc_1_1_smc(ARM_SMCCC_CPU_WORKAROUND_4193714, &res);
+	}
+}
+
 static void guest_lock_component(struct pkvm_hyp_vm *vm)
 {
 	hyp_spin_lock(&vm->lock);
@@ -574,8 +589,14 @@ static int host_stage2_set_owner_metadata_locked(phys_addr_t addr, u64 size,
 	ret = host_stage2_try(kvm_pgtable_stage2_annotate, &host_mmu.pgt,
 			      addr, size, &host_s2_pool,
 			      KVM_HOST_INVALID_PTE_TYPE_DONATION, annotation);
-	if (!ret)
+	if (!ret) {
+		/*
+		 * After stage2 maintenance has happened, but before the page
+		 * owner has changed.
+		 */
+		pkvm_sme_dvmsync_fw_call();
 		__host_update_page_state(addr, size, PKVM_NOPAGE);
+	}
 
 	return ret;
 }
@@ -1369,6 +1390,22 @@ int __pkvm_host_reclaim_page_guest(u64 gfn, struct pkvm_hyp_vm *vm)
 	return ret && ret != -EHWPOISON ? ret : 0;
 }
 
+/*
+ * share/donate install at most one stage-2 leaf (PAGE_SIZE, or one
+ * KVM_PGTABLE_LAST_LEVEL - 1 block for share). kvm_mmu_cache_min_pages()
+ * bounds the worst-case allocation: exact for the PAGE_SIZE leaf,
+ * conservative by one for the block.
+ */
+static int __guest_check_pgtable_memcache(struct pkvm_hyp_vcpu *vcpu)
+{
+	struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu);
+
+	if (vcpu->vcpu.arch.pkvm_memcache.nr_pages < kvm_mmu_cache_min_pages(vm->pgt.mmu))
+		return -ENOMEM;
+
+	return 0;
+}
+
 int __pkvm_host_donate_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu)
 {
 	struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu);
@@ -1388,6 +1425,10 @@ int __pkvm_host_donate_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu)
 	if (ret)
 		goto unlock;
 
+	ret = __guest_check_pgtable_memcache(vcpu);
+	if (ret)
+		goto unlock;
+
 	meta = host_stage2_encode_gfn_meta(vm, gfn);
 	WARN_ON(host_stage2_set_owner_metadata_locked(phys, PAGE_SIZE,
 						      PKVM_ID_GUEST, meta));
@@ -1453,6 +1494,10 @@ int __pkvm_host_share_guest(u64 pfn, u64 gfn, u64 nr_pages, struct pkvm_hyp_vcpu
 		}
 	}
 
+	ret = __guest_check_pgtable_memcache(vcpu);
+	if (ret)
+		goto unlock;
+
 	for_each_hyp_page(page, phys, size) {
 		set_host_state(page, PKVM_PAGE_SHARED_OWNED);
 		page->host_share_guest_count++;

arch/arm64/kvm/hyp/nvhe/pkvm.c

@@ -752,16 +752,30 @@ static struct pkvm_hyp_vcpu selftest_vcpu = {
 struct pkvm_hyp_vcpu *init_selftest_vm(void *virt)
 {
 	struct hyp_page *p = hyp_virt_to_page(virt);
+	unsigned long min_pages, seeded = 0;
 	int i;
 
 	selftest_vm.kvm.arch.mmu.vtcr = host_mmu.arch.mmu.vtcr;
 	WARN_ON(kvm_guest_prepare_stage2(&selftest_vm, virt));
 
+	/*
+	 * Mirror pkvm_refill_memcache() for the share/donate pre-checks;
+	 * the selftest invokes those functions directly and would
+	 * otherwise see an empty memcache.
+	 */
+	min_pages = kvm_mmu_cache_min_pages(&selftest_vm.kvm.arch.mmu);
+
 	for (i = 0; i < pkvm_selftest_pages(); i++) {
 		if (p[i].refcount)
 			continue;
 		p[i].refcount = 1;
-		hyp_put_page(&selftest_vm.pool, hyp_page_to_virt(&p[i]));
+		if (seeded < min_pages) {
+			push_hyp_memcache(&selftest_vcpu.vcpu.arch.pkvm_memcache,
+					  hyp_page_to_virt(&p[i]), hyp_virt_to_phys);
+			seeded++;
+		} else {
+			hyp_put_page(&selftest_vm.pool, hyp_page_to_virt(&p[i]));
+		}
 	}
 
 	selftest_vm.kvm.arch.pkvm.handle = __pkvm_reserve_vm();

arch/arm64/kvm/hyp/vhe/switch.c

@@ -663,7 +663,8 @@ static void __noreturn __hyp_call_panic(u64 spsr, u64 elr, u64 par)
 	host_ctxt = host_data_ptr(host_ctxt);
 	vcpu = host_ctxt->__hyp_running_vcpu;
 
-	__deactivate_traps(vcpu);
+	if (vcpu)
+		__deactivate_traps(vcpu);
 	sysreg_restore_host_state_vhe(host_ctxt);
 
 	panic("HYP panic:\nPS:%08llx PC:%016llx ESR:%08llx\nFAR:%016llx HPFAR:%016llx PAR:%016llx\nVCPU:%p\n",

arch/arm64/kvm/mmu.c

@@ -1576,21 +1576,24 @@ struct kvm_s2_fault_desc {
 static int gmem_abort(const struct kvm_s2_fault_desc *s2fd)
 {
 	bool write_fault, exec_fault;
+	bool perm_fault = kvm_vcpu_trap_is_permission_fault(s2fd->vcpu);
 	enum kvm_pgtable_walk_flags flags = KVM_PGTABLE_WALK_SHARED;
 	enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R;
 	struct kvm_pgtable *pgt = s2fd->vcpu->arch.hw_mmu->pgt;
 	unsigned long mmu_seq;
 	struct page *page;
 	struct kvm *kvm = s2fd->vcpu->kvm;
-	void *memcache;
+	void *memcache = NULL;
 	kvm_pfn_t pfn;
 	gfn_t gfn;
 	int ret;
 
-	memcache = get_mmu_memcache(s2fd->vcpu);
-	ret = topup_mmu_memcache(s2fd->vcpu, memcache);
-	if (ret)
-		return ret;
+	if (!perm_fault) {
+		memcache = get_mmu_memcache(s2fd->vcpu);
+		ret = topup_mmu_memcache(s2fd->vcpu, memcache);
+		if (ret)
+			return ret;
+	}
 
 	if (s2fd->nested)
 		gfn = kvm_s2_trans_output(s2fd->nested) >> PAGE_SHIFT;
@@ -1631,9 +1634,19 @@ static int gmem_abort(const struct kvm_s2_fault_desc *s2fd)
 		goto out_unlock;
 	}
 
-	ret = KVM_PGT_FN(kvm_pgtable_stage2_map)(pgt, s2fd->fault_ipa, PAGE_SIZE,
-						 __pfn_to_phys(pfn), prot,
-						 memcache, flags);
+	if (perm_fault) {
+		/*
+		 * Drop the SW bits in favour of those stored in the
+		 * PTE, which will be preserved.
+		 */
+		prot &= ~KVM_NV_GUEST_MAP_SZ;
+		ret = KVM_PGT_FN(kvm_pgtable_stage2_relax_perms)(pgt, s2fd->fault_ipa,
+								 prot, flags);
+	} else {
+		ret = KVM_PGT_FN(kvm_pgtable_stage2_map)(pgt, s2fd->fault_ipa, PAGE_SIZE,
+							 __pfn_to_phys(pfn), prot,
+							 memcache, flags);
+	}
 
 out_unlock:
 	kvm_release_faultin_page(kvm, page, !!ret, prot & KVM_PGTABLE_PROT_W);

include/linux/arm-smccc.h

@@ -105,6 +105,12 @@
 			   ARM_SMCCC_SMC_32,				\
 			   0, 0x3fff)
 
+/* C1-Pro erratum 4193714: SME DVMSync early acknowledgement */
+#define ARM_SMCCC_CPU_WORKAROUND_4193714				\
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
+			   ARM_SMCCC_SMC_32,				\
+			   ARM_SMCCC_OWNER_CPU, 0x10)
+
 #define ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID				\
 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
 			   ARM_SMCCC_SMC_32,				\

tools/testing/selftests/kvm/steal_time.c

@@ -220,6 +220,8 @@ static void check_steal_time_uapi(void)
 	};
 
 	vcpu_ioctl(vcpu, KVM_HAS_DEVICE_ATTR, &dev);
+	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, ST_GPA_BASE, 1, 1, 0);
+	virt_map(vm, ST_GPA_BASE, ST_GPA_BASE, 1);
 
 	st_ipa = (ulong)ST_GPA_BASE | 1;
 	ret = __vcpu_ioctl(vcpu, KVM_SET_DEVICE_ATTR, &dev);