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

Pull kvm updates from Paolo Bonzini:
 "The biggest change here is eliminating the awful idea that KVM had of
  essentially guessing which pfns are refcounted pages.

  The reason to do so was that KVM needs to map both non-refcounted
  pages (for example BARs of VFIO devices) and VM_PFNMAP/VM_MIXMEDMAP
  VMAs that contain refcounted pages.

  However, the result was security issues in the past, and more recently
  the inability to map VM_IO and VM_PFNMAP memory that _is_ backed by
  struct page but is not refcounted. In particular this broke virtio-gpu
  blob resources (which directly map host graphics buffers into the
  guest as "vram" for the virtio-gpu device) with the amdgpu driver,
  because amdgpu allocates non-compound higher order pages and the tail
  pages could not be mapped into KVM.

  This requires adjusting all uses of struct page in the
  per-architecture code, to always work on the pfn whenever possible.
  The large series that did this, from David Stevens and Sean
  Christopherson, also cleaned up substantially the set of functions
  that provided arch code with the pfn for a host virtual addresses.

  The previous maze of twisty little passages, all different, is
  replaced by five functions (__gfn_to_page, __kvm_faultin_pfn, the
  non-__ versions of these two, and kvm_prefetch_pages) saving almost
  200 lines of code.

  ARM:

   - Support for stage-1 permission indirection (FEAT_S1PIE) and
     permission overlays (FEAT_S1POE), including nested virt + the
     emulated page table walker

   - Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This
     call was introduced in PSCIv1.3 as a mechanism to request
     hibernation, similar to the S4 state in ACPI

   - Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As
     part of it, introduce trivial initialization of the host's MPAM
     context so KVM can use the corresponding traps

   - PMU support under nested virtualization, honoring the guest
     hypervisor's trap configuration and event filtering when running a
     nested guest

   - Fixes to vgic ITS serialization where stale device/interrupt table
     entries are not zeroed when the mapping is invalidated by the VM

   - Avoid emulated MMIO completion if userspace has requested
     synchronous external abort injection

   - Various fixes and cleanups affecting pKVM, vCPU initialization, and
     selftests

  LoongArch:

   - Add iocsr and mmio bus simulation in kernel.

   - Add in-kernel interrupt controller emulation.

   - Add support for virtualization extensions to the eiointc irqchip.

  PPC:

   - Drop lingering and utterly obsolete references to PPC970 KVM, which
     was removed 10 years ago.

   - Fix incorrect documentation references to non-existing ioctls

  RISC-V:

   - Accelerate KVM RISC-V when running as a guest

   - Perf support to collect KVM guest statistics from host side

  s390:

   - New selftests: more ucontrol selftests and CPU model sanity checks

   - Support for the gen17 CPU model

   - List registers supported by KVM_GET/SET_ONE_REG in the
     documentation

  x86:

   - Cleanup KVM's handling of Accessed and Dirty bits to dedup code,
     improve documentation, harden against unexpected changes.

     Even if the hardware A/D tracking is disabled, it is possible to
     use the hardware-defined A/D bits to track if a PFN is Accessed
     and/or Dirty, and that removes a lot of special cases.

   - Elide TLB flushes when aging secondary PTEs, as has been done in
     x86's primary MMU for over 10 years.

   - Recover huge pages in-place in the TDP MMU when dirty page logging
     is toggled off, instead of zapping them and waiting until the page
     is re-accessed to create a huge mapping. This reduces vCPU jitter.

   - Batch TLB flushes when dirty page logging is toggled off. This
     reduces the time it takes to disable dirty logging by ~3x.

   - Remove the shrinker that was (poorly) attempting to reclaim shadow
     page tables in low-memory situations.

   - Clean up and optimize KVM's handling of writes to
     MSR_IA32_APICBASE.

   - Advertise CPUIDs for new instructions in Clearwater Forest

   - Quirk KVM's misguided behavior of initialized certain feature MSRs
     to their maximum supported feature set, which can result in KVM
     creating invalid vCPU state. E.g. initializing PERF_CAPABILITIES to
     a non-zero value results in the vCPU having invalid state if
     userspace hides PDCM from the guest, which in turn can lead to
     save/restore failures.

   - Fix KVM's handling of non-canonical checks for vCPUs that support
     LA57 to better follow the "architecture", in quotes because the
     actual behavior is poorly documented. E.g. most MSR writes and
     descriptor table loads ignore CR4.LA57 and operate purely on
     whether the CPU supports LA57.

   - Bypass the register cache when querying CPL from kvm_sched_out(),
     as filling the cache from IRQ context is generally unsafe; harden
     the cache accessors to try to prevent similar issues from occuring
     in the future. The issue that triggered this change was already
     fixed in 6.12, but was still kinda latent.

   - Advertise AMD_IBPB_RET to userspace, and fix a related bug where
     KVM over-advertises SPEC_CTRL when trying to support cross-vendor
     VMs.

   - Minor cleanups

   - Switch hugepage recovery thread to use vhost_task.

     These kthreads can consume significant amounts of CPU time on
     behalf of a VM or in response to how the VM behaves (for example
     how it accesses its memory); therefore KVM tried to place the
     thread in the VM's cgroups and charge the CPU time consumed by that
     work to the VM's container.

     However the kthreads did not process SIGSTOP/SIGCONT, and therefore
     cgroups which had KVM instances inside could not complete freezing.

     Fix this by replacing the kthread with a PF_USER_WORKER thread, via
     the vhost_task abstraction. Another 100+ lines removed, with
     generally better behavior too like having these threads properly
     parented in the process tree.

   - Revert a workaround for an old CPU erratum (Nehalem/Westmere) that
     didn't really work; there was really nothing to work around anyway:
     the broken patch was meant to fix nested virtualization, but the
     PERF_GLOBAL_CTRL MSR is virtualized and therefore unaffected by the
     erratum.

   - Fix 6.12 regression where CONFIG_KVM will be built as a module even
     if asked to be builtin, as long as neither KVM_INTEL nor KVM_AMD is
     'y'.

  x86 selftests:

   - x86 selftests can now use AVX.

  Documentation:

   - Use rST internal links

   - Reorganize the introduction to the API document

  Generic:

   - Protect vcpu->pid accesses outside of vcpu->mutex with a rwlock
     instead of RCU, so that running a vCPU on a different task doesn't
     encounter long due to having to wait for all CPUs become quiescent.

     In general both reads and writes are rare, but userspace that
     supports confidential computing is introducing the use of "helper"
     vCPUs that may jump from one host processor to another. Those will
     be very happy to trigger a synchronize_rcu(), and the effect on
     performance is quite the disaster"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (298 commits)
  KVM: x86: Break CONFIG_KVM_X86's direct dependency on KVM_INTEL || KVM_AMD
  KVM: x86: add back X86_LOCAL_APIC dependency
  Revert "KVM: VMX: Move LOAD_IA32_PERF_GLOBAL_CTRL errata handling out of setup_vmcs_config()"
  KVM: x86: switch hugepage recovery thread to vhost_task
  KVM: x86: expose MSR_PLATFORM_INFO as a feature MSR
  x86: KVM: Advertise CPUIDs for new instructions in Clearwater Forest
  Documentation: KVM: fix malformed table
  irqchip/loongson-eiointc: Add virt extension support
  LoongArch: KVM: Add irqfd support
  LoongArch: KVM: Add PCHPIC user mode read and write functions
  LoongArch: KVM: Add PCHPIC read and write functions
  LoongArch: KVM: Add PCHPIC device support
  LoongArch: KVM: Add EIOINTC user mode read and write functions
  LoongArch: KVM: Add EIOINTC read and write functions
  LoongArch: KVM: Add EIOINTC device support
  LoongArch: KVM: Add IPI user mode read and write function
  LoongArch: KVM: Add IPI read and write function
  LoongArch: KVM: Add IPI device support
  LoongArch: KVM: Add iocsr and mmio bus simulation in kernel
  KVM: arm64: Pass on SVE mapping failures
  ...

1 files changed, 42 insertions, 35 deletions

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 931a7361c30f..aa78b6f38dfe 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -7,6 +7,7 @@
 #include <asm/debugreg.h>
 #include <asm/mmu_context.h>
 
+#include "x86.h"
 #include "cpuid.h"
 #include "hyperv.h"
 #include "mmu.h"
@@ -16,7 +17,6 @@
 #include "sgx.h"
 #include "trace.h"
 #include "vmx.h"
-#include "x86.h"
 #include "smm.h"
 
 static bool __read_mostly enable_shadow_vmcs = 1;
@@ -231,11 +231,8 @@ static inline void nested_release_evmcs(struct kvm_vcpu *vcpu)
 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 
-	if (nested_vmx_is_evmptr12_valid(vmx)) {
-		kvm_vcpu_unmap(vcpu, &vmx->nested.hv_evmcs_map, true);
-		vmx->nested.hv_evmcs = NULL;
-	}
-
+	kvm_vcpu_unmap(vcpu, &vmx->nested.hv_evmcs_map);
+	vmx->nested.hv_evmcs = NULL;
 	vmx->nested.hv_evmcs_vmptr = EVMPTR_INVALID;
 
 	if (hv_vcpu) {
@@ -317,6 +314,16 @@ static void vmx_switch_vmcs(struct kvm_vcpu *vcpu, struct loaded_vmcs *vmcs)
 	vcpu->arch.regs_dirty = 0;
 }
 
+static void nested_put_vmcs12_pages(struct kvm_vcpu *vcpu)
+{
+	struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+	kvm_vcpu_unmap(vcpu, &vmx->nested.apic_access_page_map);
+	kvm_vcpu_unmap(vcpu, &vmx->nested.virtual_apic_map);
+	kvm_vcpu_unmap(vcpu, &vmx->nested.pi_desc_map);
+	vmx->nested.pi_desc = NULL;
+}
+
 /*
  * Free whatever needs to be freed from vmx->nested when L1 goes down, or
  * just stops using VMX.
@@ -349,15 +356,8 @@ static void free_nested(struct kvm_vcpu *vcpu)
 	vmx->nested.cached_vmcs12 = NULL;
 	kfree(vmx->nested.cached_shadow_vmcs12);
 	vmx->nested.cached_shadow_vmcs12 = NULL;
-	/*
-	 * Unpin physical memory we referred to in the vmcs02.  The APIC access
-	 * page's backing page (yeah, confusing) shouldn't actually be accessed,
-	 * and if it is written, the contents are irrelevant.
-	 */
-	kvm_vcpu_unmap(vcpu, &vmx->nested.apic_access_page_map, false);
-	kvm_vcpu_unmap(vcpu, &vmx->nested.virtual_apic_map, true);
-	kvm_vcpu_unmap(vcpu, &vmx->nested.pi_desc_map, true);
-	vmx->nested.pi_desc = NULL;
+
+	nested_put_vmcs12_pages(vcpu);
 
 	kvm_mmu_free_roots(vcpu->kvm, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL);
 
@@ -624,7 +624,7 @@ static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu,
 	int msr;
 	unsigned long *msr_bitmap_l1;
 	unsigned long *msr_bitmap_l0 = vmx->nested.vmcs02.msr_bitmap;
-	struct kvm_host_map *map = &vmx->nested.msr_bitmap_map;
+	struct kvm_host_map map;
 
 	/* Nothing to do if the MSR bitmap is not in use.  */
 	if (!cpu_has_vmx_msr_bitmap() ||
@@ -647,10 +647,10 @@ static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu,
 			return true;
 	}
 
-	if (kvm_vcpu_map(vcpu, gpa_to_gfn(vmcs12->msr_bitmap), map))
+	if (kvm_vcpu_map_readonly(vcpu, gpa_to_gfn(vmcs12->msr_bitmap), &map))
 		return false;
 
-	msr_bitmap_l1 = (unsigned long *)map->hva;
+	msr_bitmap_l1 = (unsigned long *)map.hva;
 
 	/*
 	 * To keep the control flow simple, pay eight 8-byte writes (sixteen
@@ -714,7 +714,7 @@ static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu,
 	nested_vmx_set_intercept_for_msr(vmx, msr_bitmap_l1, msr_bitmap_l0,
 					 MSR_IA32_FLUSH_CMD, MSR_TYPE_W);
 
-	kvm_vcpu_unmap(vcpu, &vmx->nested.msr_bitmap_map, false);
+	kvm_vcpu_unmap(vcpu, &map);
 
 	vmx->nested.force_msr_bitmap_recalc = false;
 
@@ -3010,6 +3010,17 @@ static int nested_vmx_check_address_space_size(struct kvm_vcpu *vcpu,
 	return 0;
 }
 
+static bool is_l1_noncanonical_address_on_vmexit(u64 la, struct vmcs12 *vmcs12)
+{
+	/*
+	 * Check that the given linear address is canonical after a VM exit
+	 * from L2, based on HOST_CR4.LA57 value that will be loaded for L1.
+	 */
+	u8 l1_address_bits_on_exit = (vmcs12->host_cr4 & X86_CR4_LA57) ? 57 : 48;
+
+	return !__is_canonical_address(la, l1_address_bits_on_exit);
+}
+
 static int nested_vmx_check_host_state(struct kvm_vcpu *vcpu,
 				       struct vmcs12 *vmcs12)
 {
@@ -3020,8 +3031,8 @@ static int nested_vmx_check_host_state(struct kvm_vcpu *vcpu,
 	    CC(!kvm_vcpu_is_legal_cr3(vcpu, vmcs12->host_cr3)))
 		return -EINVAL;
 
-	if (CC(is_noncanonical_address(vmcs12->host_ia32_sysenter_esp, vcpu)) ||
-	    CC(is_noncanonical_address(vmcs12->host_ia32_sysenter_eip, vcpu)))
+	if (CC(is_noncanonical_msr_address(vmcs12->host_ia32_sysenter_esp, vcpu)) ||
+	    CC(is_noncanonical_msr_address(vmcs12->host_ia32_sysenter_eip, vcpu)))
 		return -EINVAL;
 
 	if ((vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PAT) &&
@@ -3055,12 +3066,12 @@ static int nested_vmx_check_host_state(struct kvm_vcpu *vcpu,
 	    CC(vmcs12->host_ss_selector == 0 && !ia32e))
 		return -EINVAL;
 
-	if (CC(is_noncanonical_address(vmcs12->host_fs_base, vcpu)) ||
-	    CC(is_noncanonical_address(vmcs12->host_gs_base, vcpu)) ||
-	    CC(is_noncanonical_address(vmcs12->host_gdtr_base, vcpu)) ||
-	    CC(is_noncanonical_address(vmcs12->host_idtr_base, vcpu)) ||
-	    CC(is_noncanonical_address(vmcs12->host_tr_base, vcpu)) ||
-	    CC(is_noncanonical_address(vmcs12->host_rip, vcpu)))
+	if (CC(is_noncanonical_base_address(vmcs12->host_fs_base, vcpu)) ||
+	    CC(is_noncanonical_base_address(vmcs12->host_gs_base, vcpu)) ||
+	    CC(is_noncanonical_base_address(vmcs12->host_gdtr_base, vcpu)) ||
+	    CC(is_noncanonical_base_address(vmcs12->host_idtr_base, vcpu)) ||
+	    CC(is_noncanonical_base_address(vmcs12->host_tr_base, vcpu)) ||
+	    CC(is_l1_noncanonical_address_on_vmexit(vmcs12->host_rip, vmcs12)))
 		return -EINVAL;
 
 	/*
@@ -3178,7 +3189,7 @@ static int nested_vmx_check_guest_state(struct kvm_vcpu *vcpu,
 	}
 
 	if ((vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS) &&
-	    (CC(is_noncanonical_address(vmcs12->guest_bndcfgs & PAGE_MASK, vcpu)) ||
+	    (CC(is_noncanonical_msr_address(vmcs12->guest_bndcfgs & PAGE_MASK, vcpu)) ||
 	     CC((vmcs12->guest_bndcfgs & MSR_IA32_BNDCFGS_RSVD))))
 		return -EINVAL;
 
@@ -5027,11 +5038,7 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
 		vmx_update_cpu_dirty_logging(vcpu);
 	}
 
-	/* Unpin physical memory we referred to in vmcs02 */
-	kvm_vcpu_unmap(vcpu, &vmx->nested.apic_access_page_map, false);
-	kvm_vcpu_unmap(vcpu, &vmx->nested.virtual_apic_map, true);
-	kvm_vcpu_unmap(vcpu, &vmx->nested.pi_desc_map, true);
-	vmx->nested.pi_desc = NULL;
+	nested_put_vmcs12_pages(vcpu);
 
 	if (vmx->nested.reload_vmcs01_apic_access_page) {
 		vmx->nested.reload_vmcs01_apic_access_page = false;
@@ -5167,7 +5174,7 @@ int get_vmx_mem_address(struct kvm_vcpu *vcpu, unsigned long exit_qualification,
 		 * non-canonical form. This is the only check on the memory
 		 * destination for long mode!
 		 */
-		exn = is_noncanonical_address(*ret, vcpu);
+		exn = is_noncanonical_address(*ret, vcpu, 0);
 	} else {
 		/*
 		 * When not in long mode, the virtual/linear address is
@@ -5978,7 +5985,7 @@ static int handle_invvpid(struct kvm_vcpu *vcpu)
 		 * invalidation.
 		 */
 		if (!operand.vpid ||
-		    is_noncanonical_address(operand.gla, vcpu))
+		    is_noncanonical_invlpg_address(operand.gla, vcpu))
 			return nested_vmx_fail(vcpu,
 				VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID);
 		vpid_sync_vcpu_addr(vpid02, operand.gla);