Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "ARM:

   - Support for userspace handling of synchronous external aborts
     (SEAs), allowing the VMM to potentially handle the abort in a
     non-fatal manner

   - Large rework of the VGIC's list register handling with the goal of
     supporting more active/pending IRQs than available list registers
     in hardware. In addition, the VGIC now supports EOImode==1 style
     deactivations for IRQs which may occur on a separate vCPU than the
     one that acked the IRQ

   - Support for FEAT_XNX (user / privileged execute permissions) and
     FEAT_HAF (hardware update to the Access Flag) in the software page
     table walkers and shadow MMU

   - Allow page table destruction to reschedule, fixing long
     need_resched latencies observed when destroying a large VM

   - Minor fixes to KVM and selftests

  Loongarch:

   - Get VM PMU capability from HW GCFG register

   - Add AVEC basic support

   - Use 64-bit register definition for EIOINTC

   - Add KVM timer test cases for tools/selftests

  RISC/V:

   - SBI message passing (MPXY) support for KVM guest

   - Give a new, more specific error subcode for the case when in-kernel
     AIA virtualization fails to allocate IMSIC VS-file

   - Support KVM_DIRTY_LOG_INITIALLY_SET, enabling dirty log gradually
     in small chunks

   - Fix guest page fault within HLV* instructions

   - Flush VS-stage TLB after VCPU migration for Andes cores

  s390:

   - Always allocate ESCA (Extended System Control Area), instead of
     starting with the basic SCA and converting to ESCA with the
     addition of the 65th vCPU. The price is increased number of exits
     (and worse performance) on z10 and earlier processor; ESCA was
     introduced by z114/z196 in 2010

   - VIRT_XFER_TO_GUEST_WORK support

   - Operation exception forwarding support

   - Cleanups

  x86:

   - Skip the costly "zap all SPTEs" on an MMIO generation wrap if MMIO
     SPTE caching is disabled, as there can't be any relevant SPTEs to
     zap

   - Relocate a misplaced export

   - Fix an async #PF bug where KVM would clear the completion queue
     when the guest transitioned in and out of paging mode, e.g. when
     handling an SMI and then returning to paged mode via RSM

   - Leave KVM's user-return notifier registered even when disabling
     virtualization, as long as kvm.ko is loaded. On reboot/shutdown,
     keeping the notifier registered is ok; the kernel does not use the
     MSRs and the callback will run cleanly and restore host MSRs if the
     CPU manages to return to userspace before the system goes down

   - Use the checked version of {get,put}_user()

   - Fix a long-lurking bug where KVM's lack of catch-up logic for
     periodic APIC timers can result in a hard lockup in the host

   - Revert the periodic kvmclock sync logic now that KVM doesn't use a
     clocksource that's subject to NTP corrections

   - Clean up KVM's handling of MMIO Stale Data and L1TF, and bury the
     latter behind CONFIG_CPU_MITIGATIONS

   - Context switch XCR0, XSS, and PKRU outside of the entry/exit fast
     path; the only reason they were handled in the fast path was to
     paper of a bug in the core #MC code, and that has long since been
     fixed

   - Add emulator support for AVX MOV instructions, to play nice with
     emulated devices whose guest drivers like to access PCI BARs with
     large multi-byte instructions

  x86 (AMD):

   - Fix a few missing "VMCB dirty" bugs

   - Fix the worst of KVM's lack of EFER.LMSLE emulation

   - Add AVIC support for addressing 4k vCPUs in x2AVIC mode

   - Fix incorrect handling of selective CR0 writes when checking
     intercepts during emulation of L2 instructions

   - Fix a currently-benign bug where KVM would clobber SPEC_CTRL[63:32]
     on VMRUN and #VMEXIT

   - Fix a bug where KVM corrupt the guest code stream when re-injecting
     a soft interrupt if the guest patched the underlying code after the
     VM-Exit, e.g. when Linux patches code with a temporary INT3

   - Add KVM_X86_SNP_POLICY_BITS to advertise supported SNP policy bits
     to userspace, and extend KVM "support" to all policy bits that
     don't require any actual support from KVM

  x86 (Intel):

   - Use the root role from kvm_mmu_page to construct EPTPs instead of
     the current vCPU state, partly as worthwhile cleanup, but mostly to
     pave the way for tracking per-root TLB flushes, and elide EPT
     flushes on pCPU migration if the root is clean from a previous
     flush

   - Add a few missing nested consistency checks

   - Rip out support for doing "early" consistency checks via hardware
     as the functionality hasn't been used in years and is no longer
     useful in general; replace it with an off-by-default module param
     to WARN if hardware fails a check that KVM does not perform

   - Fix a currently-benign bug where KVM would drop the guest's
     SPEC_CTRL[63:32] on VM-Enter

   - Misc cleanups

   - Overhaul the TDX code to address systemic races where KVM (acting
     on behalf of userspace) could inadvertantly trigger lock contention
     in the TDX-Module; KVM was either working around these in weird,
     ugly ways, or was simply oblivious to them (though even Yan's
     devilish selftests could only break individual VMs, not the host
     kernel)

   - Fix a bug where KVM could corrupt a vCPU's cpu_list when freeing a
     TDX vCPU, if creating said vCPU failed partway through

   - Fix a few sparse warnings (bad annotation, 0 != NULL)

   - Use struct_size() to simplify copying TDX capabilities to userspace

   - Fix a bug where TDX would effectively corrupt user-return MSR
     values if the TDX Module rejects VP.ENTER and thus doesn't clobber
     host MSRs as expected

  Selftests:

   - Fix a math goof in mmu_stress_test when running on a single-CPU
     system/VM

   - Forcefully override ARCH from x86_64 to x86 to play nice with
     specifying ARCH=x86_64 on the command line

   - Extend a bunch of nested VMX to validate nested SVM as well

   - Add support for LA57 in the core VM_MODE_xxx macro, and add a test
     to verify KVM can save/restore nested VMX state when L1 is using
     5-level paging, but L2 is not

   - Clean up the guest paging code in anticipation of sharing the core
     logic for nested EPT and nested NPT

  guest_memfd:

   - Add NUMA mempolicy support for guest_memfd, and clean up a variety
     of rough edges in guest_memfd along the way

   - Define a CLASS to automatically handle get+put when grabbing a
     guest_memfd from a memslot to make it harder to leak references

   - Enhance KVM selftests to make it easer to develop and debug
     selftests like those added for guest_memfd NUMA support, e.g. where
     test and/or KVM bugs often result in hard-to-debug SIGBUS errors

   - Misc cleanups

  Generic:

   - Use the recently-added WQ_PERCPU when creating the per-CPU
     workqueue for irqfd cleanup

   - Fix a goof in the dirty ring documentation

   - Fix choice of target for directed yield across different calls to
     kvm_vcpu_on_spin(); the function was always starting from the first
     vCPU instead of continuing the round-robin search"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (260 commits)
  KVM: arm64: at: Update AF on software walk only if VM has FEAT_HAFDBS
  KVM: arm64: at: Use correct HA bit in TCR_EL2 when regime is EL2
  KVM: arm64: Document KVM_PGTABLE_PROT_{UX,PX}
  KVM: arm64: Fix spelling mistake "Unexpeced" -> "Unexpected"
  KVM: arm64: Add break to default case in kvm_pgtable_stage2_pte_prot()
  KVM: arm64: Add endian casting to kvm_swap_s[12]_desc()
  KVM: arm64: Fix compilation when CONFIG_ARM64_USE_LSE_ATOMICS=n
  KVM: arm64: selftests: Add test for AT emulation
  KVM: arm64: nv: Expose hardware access flag management to NV guests
  KVM: arm64: nv: Implement HW access flag management in stage-2 SW PTW
  KVM: arm64: Implement HW access flag management in stage-1 SW PTW
  KVM: arm64: Propagate PTW errors up to AT emulation
  KVM: arm64: Add helper for swapping guest descriptor
  KVM: arm64: nv: Use pgtable definitions in stage-2 walk
  KVM: arm64: Handle endianness in read helper for emulated PTW
  KVM: arm64: nv: Stop passing vCPU through void ptr in S2 PTW
  KVM: arm64: Call helper for reading descriptors directly
  KVM: arm64: nv: Advertise support for FEAT_XNX
  KVM: arm64: Teach ptdump about FEAT_XNX permissions
  KVM: s390: Use generic VIRT_XFER_TO_GUEST_WORK functions
  ...

1 files changed, 124 insertions, 8 deletions

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 9a6a80c3fbe5..48d7c372a4cd 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -904,6 +904,38 @@ static int kvm_init_ipa_range(struct kvm_s2_mmu *mmu, unsigned long type)
 	return 0;
 }
 
+/*
+ * Assume that @pgt is valid and unlinked from the KVM MMU to free the
+ * page-table without taking the kvm_mmu_lock and without performing any
+ * TLB invalidations.
+ *
+ * Also, the range of addresses can be large enough to cause need_resched
+ * warnings, for instance on CONFIG_PREEMPT_NONE kernels. Hence, invoke
+ * cond_resched() periodically to prevent hogging the CPU for a long time
+ * and schedule something else, if required.
+ */
+static void stage2_destroy_range(struct kvm_pgtable *pgt, phys_addr_t addr,
+				   phys_addr_t end)
+{
+	u64 next;
+
+	do {
+		next = stage2_range_addr_end(addr, end);
+		KVM_PGT_FN(kvm_pgtable_stage2_destroy_range)(pgt, addr,
+							     next - addr);
+		if (next != end)
+			cond_resched();
+	} while (addr = next, addr != end);
+}
+
+static void kvm_stage2_destroy(struct kvm_pgtable *pgt)
+{
+	unsigned int ia_bits = VTCR_EL2_IPA(pgt->mmu->vtcr);
+
+	stage2_destroy_range(pgt, 0, BIT(ia_bits));
+	KVM_PGT_FN(kvm_pgtable_stage2_destroy_pgd)(pgt);
+}
+
 /**
  * kvm_init_stage2_mmu - Initialise a S2 MMU structure
  * @kvm:	The pointer to the KVM structure
@@ -980,7 +1012,7 @@ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long t
 	return 0;
 
 out_destroy_pgtable:
-	KVM_PGT_FN(kvm_pgtable_stage2_destroy)(pgt);
+	kvm_stage2_destroy(pgt);
 out_free_pgtable:
 	kfree(pgt);
 	return err;
@@ -1081,7 +1113,7 @@ void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu)
 	write_unlock(&kvm->mmu_lock);
 
 	if (pgt) {
-		KVM_PGT_FN(kvm_pgtable_stage2_destroy)(pgt);
+		kvm_stage2_destroy(pgt);
 		kfree(pgt);
 	}
 }
@@ -1521,6 +1553,16 @@ static void adjust_nested_fault_perms(struct kvm_s2_trans *nested,
 	*prot |= kvm_encode_nested_level(nested);
 }
 
+static void adjust_nested_exec_perms(struct kvm *kvm,
+				     struct kvm_s2_trans *nested,
+				     enum kvm_pgtable_prot *prot)
+{
+	if (!kvm_s2_trans_exec_el0(kvm, nested))
+		*prot &= ~KVM_PGTABLE_PROT_UX;
+	if (!kvm_s2_trans_exec_el1(kvm, nested))
+		*prot &= ~KVM_PGTABLE_PROT_PX;
+}
+
 #define KVM_PGTABLE_WALK_MEMABORT_FLAGS (KVM_PGTABLE_WALK_HANDLE_FAULT | KVM_PGTABLE_WALK_SHARED)
 
 static int gmem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
@@ -1572,11 +1614,12 @@ static int gmem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 	if (writable)
 		prot |= KVM_PGTABLE_PROT_W;
 
-	if (exec_fault ||
-	    (cpus_have_final_cap(ARM64_HAS_CACHE_DIC) &&
-	     (!nested || kvm_s2_trans_executable(nested))))
+	if (exec_fault || cpus_have_final_cap(ARM64_HAS_CACHE_DIC))
 		prot |= KVM_PGTABLE_PROT_X;
 
+	if (nested)
+		adjust_nested_exec_perms(kvm, nested, &prot);
+
 	kvm_fault_lock(kvm);
 	if (mmu_invalidate_retry(kvm, mmu_seq)) {
 		ret = -EAGAIN;
@@ -1851,11 +1894,13 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 			prot |= KVM_PGTABLE_PROT_NORMAL_NC;
 		else
 			prot |= KVM_PGTABLE_PROT_DEVICE;
-	} else if (cpus_have_final_cap(ARM64_HAS_CACHE_DIC) &&
-		   (!nested || kvm_s2_trans_executable(nested))) {
+	} else if (cpus_have_final_cap(ARM64_HAS_CACHE_DIC)) {
 		prot |= KVM_PGTABLE_PROT_X;
 	}
 
+	if (nested)
+		adjust_nested_exec_perms(kvm, nested, &prot);
+
 	/*
 	 * Under the premise of getting a FSC_PERM fault, we just need to relax
 	 * permissions only if vma_pagesize equals fault_granule. Otherwise,
@@ -1899,8 +1944,48 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
 	read_unlock(&vcpu->kvm->mmu_lock);
 }
 
+/*
+ * Returns true if the SEA should be handled locally within KVM if the abort
+ * is caused by a kernel memory allocation (e.g. stage-2 table memory).
+ */
+static bool host_owns_sea(struct kvm_vcpu *vcpu, u64 esr)
+{
+	/*
+	 * Without FEAT_RAS HCR_EL2.TEA is RES0, meaning any external abort
+	 * taken from a guest EL to EL2 is due to a host-imposed access (e.g.
+	 * stage-2 PTW).
+	 */
+	if (!cpus_have_final_cap(ARM64_HAS_RAS_EXTN))
+		return true;
+
+	/* KVM owns the VNCR when the vCPU isn't in a nested context. */
+	if (is_hyp_ctxt(vcpu) && !kvm_vcpu_trap_is_iabt(vcpu) && (esr & ESR_ELx_VNCR))
+		return true;
+
+	/*
+	 * Determining if an external abort during a table walk happened at
+	 * stage-2 is only possible with S1PTW is set. Otherwise, since KVM
+	 * sets HCR_EL2.TEA, SEAs due to a stage-1 walk (i.e. accessing the
+	 * PA of the stage-1 descriptor) can reach here and are reported
+	 * with a TTW ESR value.
+	 */
+	return (esr_fsc_is_sea_ttw(esr) && (esr & ESR_ELx_S1PTW));
+}
+
 int kvm_handle_guest_sea(struct kvm_vcpu *vcpu)
 {
+	struct kvm *kvm = vcpu->kvm;
+	struct kvm_run *run = vcpu->run;
+	u64 esr = kvm_vcpu_get_esr(vcpu);
+	u64 esr_mask = ESR_ELx_EC_MASK	|
+		       ESR_ELx_IL	|
+		       ESR_ELx_FnV	|
+		       ESR_ELx_EA	|
+		       ESR_ELx_CM	|
+		       ESR_ELx_WNR	|
+		       ESR_ELx_FSC;
+	u64 ipa;
+
 	/*
 	 * Give APEI the opportunity to claim the abort before handling it
 	 * within KVM. apei_claim_sea() expects to be called with IRQs enabled.
@@ -1909,7 +1994,33 @@ int kvm_handle_guest_sea(struct kvm_vcpu *vcpu)
 	if (apei_claim_sea(NULL) == 0)
 		return 1;
 
-	return kvm_inject_serror(vcpu);
+	if (host_owns_sea(vcpu, esr) ||
+	    !test_bit(KVM_ARCH_FLAG_EXIT_SEA, &vcpu->kvm->arch.flags))
+		return kvm_inject_serror(vcpu);
+
+	/* ESR_ELx.SET is RES0 when FEAT_RAS isn't implemented. */
+	if (kvm_has_ras(kvm))
+		esr_mask |= ESR_ELx_SET_MASK;
+
+	/*
+	 * Exit to userspace, and provide faulting guest virtual and physical
+	 * addresses in case userspace wants to emulate SEA to guest by
+	 * writing to FAR_ELx and HPFAR_ELx registers.
+	 */
+	memset(&run->arm_sea, 0, sizeof(run->arm_sea));
+	run->exit_reason = KVM_EXIT_ARM_SEA;
+	run->arm_sea.esr = esr & esr_mask;
+
+	if (!(esr & ESR_ELx_FnV))
+		run->arm_sea.gva = kvm_vcpu_get_hfar(vcpu);
+
+	ipa = kvm_vcpu_get_fault_ipa(vcpu);
+	if (ipa != INVALID_GPA) {
+		run->arm_sea.flags |= KVM_EXIT_ARM_SEA_FLAG_GPA_VALID;
+		run->arm_sea.gpa = ipa;
+	}
+
+	return 0;
 }
 
 /**
@@ -1999,6 +2110,11 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
 		u32 esr;
 
 		ret = kvm_walk_nested_s2(vcpu, fault_ipa, &nested_trans);
+		if (ret == -EAGAIN) {
+			ret = 1;
+			goto out_unlock;
+		}
+
 		if (ret) {
 			esr = kvm_s2_trans_esr(&nested_trans);
 			kvm_inject_s2_fault(vcpu, esr);