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

Pull KVM updates from Paolo Bonzini:
 "ARM:
   - support for chained PMU counters in guests
   - improved SError handling
   - handle Neoverse N1 erratum #1349291
   - allow side-channel mitigation status to be migrated
   - standardise most AArch64 system register accesses to msr_s/mrs_s
   - fix host MPIDR corruption on 32bit
   - selftests ckleanups

  x86:
   - PMU event {white,black}listing
   - ability for the guest to disable host-side interrupt polling
   - fixes for enlightened VMCS (Hyper-V pv nested virtualization),
   - new hypercall to yield to IPI target
   - support for passing cstate MSRs through to the guest
   - lots of cleanups and optimizations

  Generic:
   - Some txt->rST conversions for the documentation"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (128 commits)
  Documentation: virtual: Add toctree hooks
  Documentation: kvm: Convert cpuid.txt to .rst
  Documentation: virtual: Convert paravirt_ops.txt to .rst
  KVM: x86: Unconditionally enable irqs in guest context
  KVM: x86: PMU Event Filter
  kvm: x86: Fix -Wmissing-prototypes warnings
  KVM: Properly check if "page" is valid in kvm_vcpu_unmap
  KVM: arm/arm64: Initialise host's MPIDRs by reading the actual register
  KVM: LAPIC: Retry tune per-vCPU timer_advance_ns if adaptive tuning goes insane
  kvm: LAPIC: write down valid APIC registers
  KVM: arm64: Migrate _elx sysreg accessors to msr_s/mrs_s
  KVM: doc: Add API documentation on the KVM_REG_ARM_WORKAROUNDS register
  KVM: arm/arm64: Add save/restore support for firmware workaround state
  arm64: KVM: Propagate full Spectre v2 workaround state to KVM guests
  KVM: arm/arm64: Support chained PMU counters
  KVM: arm/arm64: Remove pmc->bitmask
  KVM: arm/arm64: Re-create event when setting counter value
  KVM: arm/arm64: Extract duplicated code to own function
  KVM: arm/arm64: Rename kvm_pmu_{enable/disable}_counter functions
  KVM: LAPIC: ARBPRI is a reserved register for x2APIC
  ...

8 files changed, 198 insertions, 86 deletions

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 383b292966fa..2cd6250b2896 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -4081,6 +4081,32 @@ KVM_ARM_VCPU_FINALIZE call.
 See KVM_ARM_VCPU_INIT for details of vcpu features that require finalization
 using this ioctl.
 
+4.120 KVM_SET_PMU_EVENT_FILTER
+
+Capability: KVM_CAP_PMU_EVENT_FILTER
+Architectures: x86
+Type: vm ioctl
+Parameters: struct kvm_pmu_event_filter (in)
+Returns: 0 on success, -1 on error
+
+struct kvm_pmu_event_filter {
+       __u32 action;
+       __u32 nevents;
+       __u64 events[0];
+};
+
+This ioctl restricts the set of PMU events that the guest can program.
+The argument holds a list of events which will be allowed or denied.
+The eventsel+umask of each event the guest attempts to program is compared
+against the events field to determine whether the guest should have access.
+This only affects general purpose counters; fixed purpose counters can
+be disabled by changing the perfmon CPUID leaf.
+
+Valid values for 'action':
+#define KVM_PMU_EVENT_ALLOW 0
+#define KVM_PMU_EVENT_DENY 1
+
+
 5. The kvm_run structure
 ------------------------
 
@@ -4909,6 +4935,8 @@ Valid bits in args[0] are
 
 #define KVM_X86_DISABLE_EXITS_MWAIT            (1 << 0)
 #define KVM_X86_DISABLE_EXITS_HLT              (1 << 1)
+#define KVM_X86_DISABLE_EXITS_PAUSE            (1 << 2)
+#define KVM_X86_DISABLE_EXITS_CSTATE           (1 << 3)
 
 Enabling this capability on a VM provides userspace with a way to no
 longer intercept some instructions for improved latency in some
diff --git a/Documentation/virtual/kvm/arm/psci.txt b/Documentation/virtual/kvm/arm/psci.txt
index aafdab887b04..559586fc9d37 100644
--- a/Documentation/virtual/kvm/arm/psci.txt
+++ b/Documentation/virtual/kvm/arm/psci.txt
@@ -28,3 +28,34 @@ The following register is defined:
   - Allows any PSCI version implemented by KVM and compatible with
     v0.2 to be set with SET_ONE_REG
   - Affects the whole VM (even if the register view is per-vcpu)
+
+* KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
+  Holds the state of the firmware support to mitigate CVE-2017-5715, as
+  offered by KVM to the guest via a HVC call. The workaround is described
+  under SMCCC_ARCH_WORKAROUND_1 in [1].
+  Accepted values are:
+    KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL: KVM does not offer
+      firmware support for the workaround. The mitigation status for the
+      guest is unknown.
+    KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_AVAIL: The workaround HVC call is
+      available to the guest and required for the mitigation.
+    KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_REQUIRED: The workaround HVC call
+      is available to the guest, but it is not needed on this VCPU.
+
+* KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
+  Holds the state of the firmware support to mitigate CVE-2018-3639, as
+  offered by KVM to the guest via a HVC call. The workaround is described
+  under SMCCC_ARCH_WORKAROUND_2 in [1].
+  Accepted values are:
+    KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL: A workaround is not
+      available. KVM does not offer firmware support for the workaround.
+    KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_UNKNOWN: The workaround state is
+      unknown. KVM does not offer firmware support for the workaround.
+    KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL: The workaround is available,
+      and can be disabled by a vCPU. If
+      KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED is set, it is active for
+      this vCPU.
+    KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED: The workaround is
+      always active on this vCPU or it is not needed.
+
+[1] https://developer.arm.com/-/media/developer/pdf/ARM_DEN_0070A_Firmware_interfaces_for_mitigating_CVE-2017-5715.pdf
diff --git a/Documentation/virtual/kvm/cpuid.rst b/Documentation/virtual/kvm/cpuid.rst
new file mode 100644
index 000000000000..01b081f6e7ea
--- /dev/null
+++ b/Documentation/virtual/kvm/cpuid.rst
@@ -0,0 +1,107 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==============
+KVM CPUID bits
+==============
+
+:Author: Glauber Costa <glommer@gmail.com>
+
+A guest running on a kvm host, can check some of its features using
+cpuid. This is not always guaranteed to work, since userspace can
+mask-out some, or even all KVM-related cpuid features before launching
+a guest.
+
+KVM cpuid functions are:
+
+function: KVM_CPUID_SIGNATURE (0x40000000)
+
+returns::
+
+   eax = 0x40000001
+   ebx = 0x4b4d564b
+   ecx = 0x564b4d56
+   edx = 0x4d
+
+Note that this value in ebx, ecx and edx corresponds to the string "KVMKVMKVM".
+The value in eax corresponds to the maximum cpuid function present in this leaf,
+and will be updated if more functions are added in the future.
+Note also that old hosts set eax value to 0x0. This should
+be interpreted as if the value was 0x40000001.
+This function queries the presence of KVM cpuid leafs.
+
+function: define KVM_CPUID_FEATURES (0x40000001)
+
+returns::
+
+          ebx, ecx
+          eax = an OR'ed group of (1 << flag)
+
+where ``flag`` is defined as below:
+
+================================= =========== ================================
+flag                              value       meaning
+================================= =========== ================================
+KVM_FEATURE_CLOCKSOURCE           0           kvmclock available at msrs
+                                              0x11 and 0x12
+
+KVM_FEATURE_NOP_IO_DELAY          1           not necessary to perform delays
+                                              on PIO operations
+
+KVM_FEATURE_MMU_OP                2           deprecated
+
+KVM_FEATURE_CLOCKSOURCE2          3           kvmclock available at msrs
+
+                                              0x4b564d00 and 0x4b564d01
+KVM_FEATURE_ASYNC_PF              4           async pf can be enabled by
+                                              writing to msr 0x4b564d02
+
+KVM_FEATURE_STEAL_TIME            5           steal time can be enabled by
+                                              writing to msr 0x4b564d03
+
+KVM_FEATURE_PV_EOI                6           paravirtualized end of interrupt
+                                              handler can be enabled by
+                                              writing to msr 0x4b564d04
+
+KVM_FEATURE_PV_UNHAULT            7           guest checks this feature bit
+                                              before enabling paravirtualized
+                                              spinlock support
+
+KVM_FEATURE_PV_TLB_FLUSH          9           guest checks this feature bit
+                                              before enabling paravirtualized
+                                              tlb flush
+
+KVM_FEATURE_ASYNC_PF_VMEXIT       10          paravirtualized async PF VM EXIT
+                                              can be enabled by setting bit 2
+                                              when writing to msr 0x4b564d02
+
+KVM_FEATURE_PV_SEND_IPI           11          guest checks this feature bit
+                                              before enabling paravirtualized
+                                              sebd IPIs
+
+KVM_FEATURE_PV_POLL_CONTROL       12          host-side polling on HLT can
+                                              be disabled by writing
+                                              to msr 0x4b564d05.
+
+KVM_FEATURE_PV_SCHED_YIELD        13          guest checks this feature bit
+                                              before using paravirtualized
+                                              sched yield.
+
+KVM_FEATURE_CLOCSOURCE_STABLE_BIT 24          host will warn if no guest-side
+                                              per-cpu warps are expeced in
+                                              kvmclock
+================================= =========== ================================
+
+::
+
+      edx = an OR'ed group of (1 << flag)
+
+Where ``flag`` here is defined as below:
+
+================== ============ =================================
+flag               value        meaning
+================== ============ =================================
+KVM_HINTS_REALTIME 0            guest checks this feature bit to
+                                determine that vCPUs are never
+                                preempted for an unlimited time
+                                allowing optimizations
+================== ============ =================================
diff --git a/Documentation/virtual/kvm/cpuid.txt b/Documentation/virtual/kvm/cpuid.txt
deleted file mode 100644
index 97ca1940a0dc..000000000000
--- a/Documentation/virtual/kvm/cpuid.txt
+++ /dev/null
@@ -1,83 +0,0 @@
-KVM CPUID bits
-Glauber Costa <glommer@redhat.com>, Red Hat Inc, 2010
-=====================================================
-
-A guest running on a kvm host, can check some of its features using
-cpuid. This is not always guaranteed to work, since userspace can
-mask-out some, or even all KVM-related cpuid features before launching
-a guest.
-
-KVM cpuid functions are:
-
-function: KVM_CPUID_SIGNATURE (0x40000000)
-returns : eax = 0x40000001,
-          ebx = 0x4b4d564b,
-          ecx = 0x564b4d56,
-          edx = 0x4d.
-Note that this value in ebx, ecx and edx corresponds to the string "KVMKVMKVM".
-The value in eax corresponds to the maximum cpuid function present in this leaf,
-and will be updated if more functions are added in the future.
-Note also that old hosts set eax value to 0x0. This should
-be interpreted as if the value was 0x40000001.
-This function queries the presence of KVM cpuid leafs.
-
-
-function: define KVM_CPUID_FEATURES (0x40000001)
-returns : ebx, ecx
-          eax = an OR'ed group of (1 << flag), where each flags is:
-
-
-flag                               || value || meaning
-=============================================================================
-KVM_FEATURE_CLOCKSOURCE            ||     0 || kvmclock available at msrs
-                                   ||       || 0x11 and 0x12.
-------------------------------------------------------------------------------
-KVM_FEATURE_NOP_IO_DELAY           ||     1 || not necessary to perform delays
-                                   ||       || on PIO operations.
-------------------------------------------------------------------------------
-KVM_FEATURE_MMU_OP                 ||     2 || deprecated.
-------------------------------------------------------------------------------
-KVM_FEATURE_CLOCKSOURCE2           ||     3 || kvmclock available at msrs
-                                   ||       || 0x4b564d00 and 0x4b564d01
-------------------------------------------------------------------------------
-KVM_FEATURE_ASYNC_PF               ||     4 || async pf can be enabled by
-                                   ||       || writing to msr 0x4b564d02
-------------------------------------------------------------------------------
-KVM_FEATURE_STEAL_TIME             ||     5 || steal time can be enabled by
-                                   ||       || writing to msr 0x4b564d03.
-------------------------------------------------------------------------------
-KVM_FEATURE_PV_EOI                 ||     6 || paravirtualized end of interrupt
-                                   ||       || handler can be enabled by writing
-                                   ||       || to msr 0x4b564d04.
-------------------------------------------------------------------------------
-KVM_FEATURE_PV_UNHALT              ||     7 || guest checks this feature bit
-                                   ||       || before enabling paravirtualized
-                                   ||       || spinlock support.
-------------------------------------------------------------------------------
-KVM_FEATURE_PV_TLB_FLUSH           ||     9 || guest checks this feature bit
-                                   ||       || before enabling paravirtualized
-                                   ||       || tlb flush.
-------------------------------------------------------------------------------
-KVM_FEATURE_ASYNC_PF_VMEXIT        ||    10 || paravirtualized async PF VM exit
-                                   ||       || can be enabled by setting bit 2
-                                   ||       || when writing to msr 0x4b564d02
-------------------------------------------------------------------------------
-KVM_FEATURE_PV_SEND_IPI            ||    11 || guest checks this feature bit
-                                   ||       || before using paravirtualized
-                                   ||       || send IPIs.
-------------------------------------------------------------------------------
-KVM_FEATURE_CLOCKSOURCE_STABLE_BIT ||    24 || host will warn if no guest-side
-                                   ||       || per-cpu warps are expected in
-                                   ||       || kvmclock.
-------------------------------------------------------------------------------
-
-          edx = an OR'ed group of (1 << flag), where each flags is:
-
-
-flag                               || value || meaning
-==================================================================================
-KVM_HINTS_REALTIME                 ||     0 || guest checks this feature bit to
-                                   ||       || determine that vCPUs are never
-                                   ||       || preempted for an unlimited time,
-                                   ||       || allowing optimizations
-----------------------------------------------------------------------------------
diff --git a/Documentation/virtual/kvm/hypercalls.txt b/Documentation/virtual/kvm/hypercalls.txt
index da24c138c8d1..da210651f714 100644
--- a/Documentation/virtual/kvm/hypercalls.txt
+++ b/Documentation/virtual/kvm/hypercalls.txt
@@ -141,3 +141,14 @@ a0 corresponds to the APIC ID in the third argument (a2), bit 1
 corresponds to the APIC ID a2+1, and so on.
 
 Returns the number of CPUs to which the IPIs were delivered successfully.
+
+7. KVM_HC_SCHED_YIELD
+------------------------
+Architecture: x86
+Status: active
+Purpose: Hypercall used to yield if the IPI target vCPU is preempted
+
+a0: destination APIC ID
+
+Usage example: When sending a call-function IPI-many to vCPUs, yield if
+any of the IPI target vCPUs was preempted.
diff --git a/Documentation/virtual/kvm/index.rst b/Documentation/virtual/kvm/index.rst
new file mode 100644
index 000000000000..0b206a06f5be
--- /dev/null
+++ b/Documentation/virtual/kvm/index.rst
@@ -0,0 +1,11 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===
+KVM
+===
+
+.. toctree::
+   :maxdepth: 2
+
+   amd-memory-encryption
+   cpuid
diff --git a/Documentation/virtual/kvm/locking.txt b/Documentation/virtual/kvm/locking.txt
index 1bb8bcaf8497..635cd6eaf714 100644
--- a/Documentation/virtual/kvm/locking.txt
+++ b/Documentation/virtual/kvm/locking.txt
@@ -15,8 +15,6 @@ The acquisition orders for mutexes are as follows:
 
 On x86, vcpu->mutex is taken outside kvm->arch.hyperv.hv_lock.
 
-For spinlocks, kvm_lock is taken outside kvm->mmu_lock.
-
 Everything else is a leaf: no other lock is taken inside the critical
 sections.
 
@@ -169,7 +167,7 @@ which time it will be set using the Dirty tracking mechanism described above.
 ------------
 
 Name:		kvm_lock
-Type:		spinlock_t
+Type:		mutex
 Arch:		any
 Protects:	- vm_list
 
diff --git a/Documentation/virtual/kvm/msr.txt b/Documentation/virtual/kvm/msr.txt
index f3f0d57ced8e..df1f4338b3ca 100644
--- a/Documentation/virtual/kvm/msr.txt
+++ b/Documentation/virtual/kvm/msr.txt
@@ -273,3 +273,12 @@ MSR_KVM_EOI_EN: 0x4b564d04
 	guest must both read the least significant bit in the memory area and
 	clear it using a single CPU instruction, such as test and clear, or
 	compare and exchange.
+
+MSR_KVM_POLL_CONTROL: 0x4b564d05
+	Control host-side polling.
+
+	data: Bit 0 enables (1) or disables (0) host-side HLT polling logic.
+
+	KVM guests can request the host not to poll on HLT, for example if
+	they are performing polling themselves.
+