Merge tag 'kvmarm-for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm updates for 5.2

- guest SVE support
- guest Pointer Authentication support
- Better discrimination of perf counters between host and guests

Conflicts:
	include/uapi/linux/kvm.h

3 files changed, 281 insertions, 4 deletions

diff --git a/Documentation/arm64/perf.txt b/Documentation/arm64/perf.txt
new file mode 100644
index 000000000000..0d6a7d87d49e
--- /dev/null
+++ b/Documentation/arm64/perf.txt
@@ -0,0 +1,85 @@
+Perf Event Attributes
+=====================
+
+Author: Andrew Murray <andrew.murray@arm.com>
+Date: 2019-03-06
+
+exclude_user
+------------
+
+This attribute excludes userspace.
+
+Userspace always runs at EL0 and thus this attribute will exclude EL0.
+
+
+exclude_kernel
+--------------
+
+This attribute excludes the kernel.
+
+The kernel runs at EL2 with VHE and EL1 without. Guest kernels always run
+at EL1.
+
+For the host this attribute will exclude EL1 and additionally EL2 on a VHE
+system.
+
+For the guest this attribute will exclude EL1. Please note that EL2 is
+never counted within a guest.
+
+
+exclude_hv
+----------
+
+This attribute excludes the hypervisor.
+
+For a VHE host this attribute is ignored as we consider the host kernel to
+be the hypervisor.
+
+For a non-VHE host this attribute will exclude EL2 as we consider the
+hypervisor to be any code that runs at EL2 which is predominantly used for
+guest/host transitions.
+
+For the guest this attribute has no effect. Please note that EL2 is
+never counted within a guest.
+
+
+exclude_host / exclude_guest
+----------------------------
+
+These attributes exclude the KVM host and guest, respectively.
+
+The KVM host may run at EL0 (userspace), EL1 (non-VHE kernel) and EL2 (VHE
+kernel or non-VHE hypervisor).
+
+The KVM guest may run at EL0 (userspace) and EL1 (kernel).
+
+Due to the overlapping exception levels between host and guests we cannot
+exclusively rely on the PMU's hardware exception filtering - therefore we
+must enable/disable counting on the entry and exit to the guest. This is
+performed differently on VHE and non-VHE systems.
+
+For non-VHE systems we exclude EL2 for exclude_host - upon entering and
+exiting the guest we disable/enable the event as appropriate based on the
+exclude_host and exclude_guest attributes.
+
+For VHE systems we exclude EL1 for exclude_guest and exclude both EL0,EL2
+for exclude_host. Upon entering and exiting the guest we modify the event
+to include/exclude EL0 as appropriate based on the exclude_host and
+exclude_guest attributes.
+
+The statements above also apply when these attributes are used within a
+non-VHE guest however please note that EL2 is never counted within a guest.
+
+
+Accuracy
+--------
+
+On non-VHE hosts we enable/disable counters on the entry/exit of host/guest
+transition at EL2 - however there is a period of time between
+enabling/disabling the counters and entering/exiting the guest. We are
+able to eliminate counters counting host events on the boundaries of guest
+entry/exit when counting guest events by filtering out EL2 for
+exclude_host. However when using !exclude_hv there is a small blackout
+window at the guest entry/exit where host events are not captured.
+
+On VHE systems there are no blackout windows.
diff --git a/Documentation/arm64/pointer-authentication.txt b/Documentation/arm64/pointer-authentication.txt
index 5baca42ba146..fc71b33de87e 100644
--- a/Documentation/arm64/pointer-authentication.txt
+++ b/Documentation/arm64/pointer-authentication.txt
@@ -87,7 +87,21 @@ used to get and set the keys for a thread.
 Virtualization
 --------------
 
-Pointer authentication is not currently supported in KVM guests. KVM
-will mask the feature bits from ID_AA64ISAR1_EL1, and attempted use of
-the feature will result in an UNDEFINED exception being injected into
-the guest.
+Pointer authentication is enabled in KVM guest when each virtual cpu is
+initialised by passing flags KVM_ARM_VCPU_PTRAUTH_[ADDRESS/GENERIC] and
+requesting these two separate cpu features to be enabled. The current KVM
+guest implementation works by enabling both features together, so both
+these userspace flags are checked before enabling pointer authentication.
+The separate userspace flag will allow to have no userspace ABI changes
+if support is added in the future to allow these two features to be
+enabled independently of one another.
+
+As Arm Architecture specifies that Pointer Authentication feature is
+implemented along with the VHE feature so KVM arm64 ptrauth code relies
+on VHE mode to be present.
+
+Additionally, when these vcpu feature flags are not set then KVM will
+filter out the Pointer Authentication system key registers from
+KVM_GET/SET_REG_* ioctls and mask those features from cpufeature ID
+register. Any attempt to use the Pointer Authentication instructions will
+result in an UNDEFINED exception being injected into the guest.
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 8ffd9beb931b..73a501eb9291 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -1883,6 +1883,12 @@ Architectures: all
 Type: vcpu ioctl
 Parameters: struct kvm_one_reg (in)
 Returns: 0 on success, negative value on failure
+Errors:
+  ENOENT:   no such register
+  EINVAL:   invalid register ID, or no such register
+  EPERM:    (arm64) register access not allowed before vcpu finalization
+(These error codes are indicative only: do not rely on a specific error
+code being returned in a specific situation.)
 
 struct kvm_one_reg {
        __u64 id;
@@ -2120,6 +2126,37 @@ contains elements ranging from 32 to 128 bits. The index is a 32bit
 value in the kvm_regs structure seen as a 32bit array.
   0x60x0 0000 0010 <index into the kvm_regs struct:16>
 
+Specifically:
+    Encoding            Register  Bits  kvm_regs member
+----------------------------------------------------------------
+  0x6030 0000 0010 0000 X0          64  regs.regs[0]
+  0x6030 0000 0010 0002 X1          64  regs.regs[1]
+    ...
+  0x6030 0000 0010 003c X30         64  regs.regs[30]
+  0x6030 0000 0010 003e SP          64  regs.sp
+  0x6030 0000 0010 0040 PC          64  regs.pc
+  0x6030 0000 0010 0042 PSTATE      64  regs.pstate
+  0x6030 0000 0010 0044 SP_EL1      64  sp_el1
+  0x6030 0000 0010 0046 ELR_EL1     64  elr_el1
+  0x6030 0000 0010 0048 SPSR_EL1    64  spsr[KVM_SPSR_EL1] (alias SPSR_SVC)
+  0x6030 0000 0010 004a SPSR_ABT    64  spsr[KVM_SPSR_ABT]
+  0x6030 0000 0010 004c SPSR_UND    64  spsr[KVM_SPSR_UND]
+  0x6030 0000 0010 004e SPSR_IRQ    64  spsr[KVM_SPSR_IRQ]
+  0x6060 0000 0010 0050 SPSR_FIQ    64  spsr[KVM_SPSR_FIQ]
+  0x6040 0000 0010 0054 V0         128  fp_regs.vregs[0]    (*)
+  0x6040 0000 0010 0058 V1         128  fp_regs.vregs[1]    (*)
+    ...
+  0x6040 0000 0010 00d0 V31        128  fp_regs.vregs[31]   (*)
+  0x6020 0000 0010 00d4 FPSR        32  fp_regs.fpsr
+  0x6020 0000 0010 00d5 FPCR        32  fp_regs.fpcr
+
+(*) These encodings are not accepted for SVE-enabled vcpus.  See
+    KVM_ARM_VCPU_INIT.
+
+    The equivalent register content can be accessed via bits [127:0] of
+    the corresponding SVE Zn registers instead for vcpus that have SVE
+    enabled (see below).
+
 arm64 CCSIDR registers are demultiplexed by CSSELR value:
   0x6020 0000 0011 00 <csselr:8>
 
@@ -2129,6 +2166,64 @@ arm64 system registers have the following id bit patterns:
 arm64 firmware pseudo-registers have the following bit pattern:
   0x6030 0000 0014 <regno:16>
 
+arm64 SVE registers have the following bit patterns:
+  0x6080 0000 0015 00 <n:5> <slice:5>   Zn bits[2048*slice + 2047 : 2048*slice]
+  0x6050 0000 0015 04 <n:4> <slice:5>   Pn bits[256*slice + 255 : 256*slice]
+  0x6050 0000 0015 060 <slice:5>        FFR bits[256*slice + 255 : 256*slice]
+  0x6060 0000 0015 ffff                 KVM_REG_ARM64_SVE_VLS pseudo-register
+
+Access to register IDs where 2048 * slice >= 128 * max_vq will fail with
+ENOENT.  max_vq is the vcpu's maximum supported vector length in 128-bit
+quadwords: see (**) below.
+
+These registers are only accessible on vcpus for which SVE is enabled.
+See KVM_ARM_VCPU_INIT for details.
+
+In addition, except for KVM_REG_ARM64_SVE_VLS, these registers are not
+accessible until the vcpu's SVE configuration has been finalized
+using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE).  See KVM_ARM_VCPU_INIT
+and KVM_ARM_VCPU_FINALIZE for more information about this procedure.
+
+KVM_REG_ARM64_SVE_VLS is a pseudo-register that allows the set of vector
+lengths supported by the vcpu to be discovered and configured by
+userspace.  When transferred to or from user memory via KVM_GET_ONE_REG
+or KVM_SET_ONE_REG, the value of this register is of type
+__u64[KVM_ARM64_SVE_VLS_WORDS], and encodes the set of vector lengths as
+follows:
+
+__u64 vector_lengths[KVM_ARM64_SVE_VLS_WORDS];
+
+if (vq >= SVE_VQ_MIN && vq <= SVE_VQ_MAX &&
+    ((vector_lengths[(vq - KVM_ARM64_SVE_VQ_MIN) / 64] >>
+		((vq - KVM_ARM64_SVE_VQ_MIN) % 64)) & 1))
+	/* Vector length vq * 16 bytes supported */
+else
+	/* Vector length vq * 16 bytes not supported */
+
+(**) The maximum value vq for which the above condition is true is
+max_vq.  This is the maximum vector length available to the guest on
+this vcpu, and determines which register slices are visible through
+this ioctl interface.
+
+(See Documentation/arm64/sve.txt for an explanation of the "vq"
+nomenclature.)
+
+KVM_REG_ARM64_SVE_VLS is only accessible after KVM_ARM_VCPU_INIT.
+KVM_ARM_VCPU_INIT initialises it to the best set of vector lengths that
+the host supports.
+
+Userspace may subsequently modify it if desired until the vcpu's SVE
+configuration is finalized using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE).
+
+Apart from simply removing all vector lengths from the host set that
+exceed some value, support for arbitrarily chosen sets of vector lengths
+is hardware-dependent and may not be available.  Attempting to configure
+an invalid set of vector lengths via KVM_SET_ONE_REG will fail with
+EINVAL.
+
+After the vcpu's SVE configuration is finalized, further attempts to
+write this register will fail with EPERM.
+
 
 MIPS registers are mapped using the lower 32 bits.  The upper 16 of that is
 the register group type:
@@ -2181,6 +2276,12 @@ Architectures: all
 Type: vcpu ioctl
 Parameters: struct kvm_one_reg (in and out)
 Returns: 0 on success, negative value on failure
+Errors include:
+  ENOENT:   no such register
+  EINVAL:   invalid register ID, or no such register
+  EPERM:    (arm64) register access not allowed before vcpu finalization
+(These error codes are indicative only: do not rely on a specific error
+code being returned in a specific situation.)
 
 This ioctl allows to receive the value of a single register implemented
 in a vcpu. The register to read is indicated by the "id" field of the
@@ -2673,6 +2774,49 @@ Possible features:
 	- KVM_ARM_VCPU_PMU_V3: Emulate PMUv3 for the CPU.
 	  Depends on KVM_CAP_ARM_PMU_V3.
 
+	- KVM_ARM_VCPU_PTRAUTH_ADDRESS: Enables Address Pointer authentication
+	  for arm64 only.
+	  Depends on KVM_CAP_ARM_PTRAUTH_ADDRESS.
+	  If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are
+	  both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and
+	  KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be
+	  requested.
+
+	- KVM_ARM_VCPU_PTRAUTH_GENERIC: Enables Generic Pointer authentication
+	  for arm64 only.
+	  Depends on KVM_CAP_ARM_PTRAUTH_GENERIC.
+	  If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are
+	  both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and
+	  KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be
+	  requested.
+
+	- KVM_ARM_VCPU_SVE: Enables SVE for the CPU (arm64 only).
+	  Depends on KVM_CAP_ARM_SVE.
+	  Requires KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE):
+
+	   * After KVM_ARM_VCPU_INIT:
+
+	      - KVM_REG_ARM64_SVE_VLS may be read using KVM_GET_ONE_REG: the
+	        initial value of this pseudo-register indicates the best set of
+	        vector lengths possible for a vcpu on this host.
+
+	   * Before KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE):
+
+	      - KVM_RUN and KVM_GET_REG_LIST are not available;
+
+	      - KVM_GET_ONE_REG and KVM_SET_ONE_REG cannot be used to access
+	        the scalable archietctural SVE registers
+	        KVM_REG_ARM64_SVE_ZREG(), KVM_REG_ARM64_SVE_PREG() or
+	        KVM_REG_ARM64_SVE_FFR;
+
+	      - KVM_REG_ARM64_SVE_VLS may optionally be written using
+	        KVM_SET_ONE_REG, to modify the set of vector lengths available
+	        for the vcpu.
+
+	   * After KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE):
+
+	      - the KVM_REG_ARM64_SVE_VLS pseudo-register is immutable, and can
+	        no longer be written using KVM_SET_ONE_REG.
 
 4.83 KVM_ARM_PREFERRED_TARGET
 
@@ -3887,6 +4031,40 @@ number of valid entries in the 'entries' array, which is then filled.
 'index' and 'flags' fields in 'struct kvm_cpuid_entry2' are currently reserved,
 userspace should not expect to get any particular value there.
 
+4.119 KVM_ARM_VCPU_FINALIZE
+
+Architectures: arm, arm64
+Type: vcpu ioctl
+Parameters: int feature (in)
+Returns: 0 on success, -1 on error
+Errors:
+  EPERM:     feature not enabled, needs configuration, or already finalized
+  EINVAL:    feature unknown or not present
+
+Recognised values for feature:
+  arm64      KVM_ARM_VCPU_SVE (requires KVM_CAP_ARM_SVE)
+
+Finalizes the configuration of the specified vcpu feature.
+
+The vcpu must already have been initialised, enabling the affected feature, by
+means of a successful KVM_ARM_VCPU_INIT call with the appropriate flag set in
+features[].
+
+For affected vcpu features, this is a mandatory step that must be performed
+before the vcpu is fully usable.
+
+Between KVM_ARM_VCPU_INIT and KVM_ARM_VCPU_FINALIZE, the feature may be
+configured by use of ioctls such as KVM_SET_ONE_REG.  The exact configuration
+that should be performaned and how to do it are feature-dependent.
+
+Other calls that depend on a particular feature being finalized, such as
+KVM_RUN, KVM_GET_REG_LIST, KVM_GET_ONE_REG and KVM_SET_ONE_REG, will fail with
+-EPERM unless the feature has already been finalized by means of a
+KVM_ARM_VCPU_FINALIZE call.
+
+See KVM_ARM_VCPU_INIT for details of vcpu features that require finalization
+using this ioctl.
+
 5. The kvm_run structure
 ------------------------