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authorPaolo Bonzini <pbonzini@redhat.com>2020-10-20 08:14:25 -0400
committerPaolo Bonzini <pbonzini@redhat.com>2020-10-20 08:14:25 -0400
commit1b21c8db0e3b71523ada0cf568372ebfcf0d3466 (patch)
tree70e537fadc469c5fddabbdf116ea6090baaf4cf8 /Documentation/virt
parent628ade2d0816b2675ab61ba6aadfc9a94e3e1589 (diff)
parent4e5dc64c43192b4fd4c96ac150a8f013065f5f5b (diff)
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Merge tag 'kvmarm-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for Linux 5.10 - New page table code for both hypervisor and guest stage-2 - Introduction of a new EL2-private host context - Allow EL2 to have its own private per-CPU variables - Support of PMU event filtering - Complete rework of the Spectre mitigation
Diffstat (limited to 'Documentation/virt')
-rw-r--r--Documentation/virt/kvm/devices/vcpu.rst57
1 files changed, 53 insertions, 4 deletions
diff --git a/Documentation/virt/kvm/devices/vcpu.rst b/Documentation/virt/kvm/devices/vcpu.rst
index ca374d3fe085..2acec3b9ef65 100644
--- a/Documentation/virt/kvm/devices/vcpu.rst
+++ b/Documentation/virt/kvm/devices/vcpu.rst
@@ -25,8 +25,10 @@ Returns:
======= ========================================================
-EBUSY The PMU overflow interrupt is already set
- -ENXIO The overflow interrupt not set when attempting to get it
- -ENODEV PMUv3 not supported
+ -EFAULT Error reading interrupt number
+ -ENXIO PMUv3 not supported or the overflow interrupt not set
+ when attempting to get it
+ -ENODEV KVM_ARM_VCPU_PMU_V3 feature missing from VCPU
-EINVAL Invalid PMU overflow interrupt number supplied or
trying to set the IRQ number without using an in-kernel
irqchip.
@@ -45,9 +47,10 @@ all vcpus, while as an SPI it must be a separate number per vcpu.
Returns:
======= ======================================================
+ -EEXIST Interrupt number already used
-ENODEV PMUv3 not supported or GIC not initialized
- -ENXIO PMUv3 not properly configured or in-kernel irqchip not
- configured as required prior to calling this attribute
+ -ENXIO PMUv3 not supported, missing VCPU feature or interrupt
+ number not set
-EBUSY PMUv3 already initialized
======= ======================================================
@@ -55,6 +58,52 @@ Request the initialization of the PMUv3. If using the PMUv3 with an in-kernel
virtual GIC implementation, this must be done after initializing the in-kernel
irqchip.
+1.3 ATTRIBUTE: KVM_ARM_VCPU_PMU_V3_FILTER
+-----------------------------------------
+
+:Parameters: in kvm_device_attr.addr the address for a PMU event filter is a
+ pointer to a struct kvm_pmu_event_filter
+
+:Returns:
+
+ ======= ======================================================
+ -ENODEV PMUv3 not supported or GIC not initialized
+ -ENXIO PMUv3 not properly configured or in-kernel irqchip not
+ configured as required prior to calling this attribute
+ -EBUSY PMUv3 already initialized
+ -EINVAL Invalid filter range
+ ======= ======================================================
+
+Request the installation of a PMU event filter described as follows::
+
+ struct kvm_pmu_event_filter {
+ __u16 base_event;
+ __u16 nevents;
+
+ #define KVM_PMU_EVENT_ALLOW 0
+ #define KVM_PMU_EVENT_DENY 1
+
+ __u8 action;
+ __u8 pad[3];
+ };
+
+A filter range is defined as the range [@base_event, @base_event + @nevents),
+together with an @action (KVM_PMU_EVENT_ALLOW or KVM_PMU_EVENT_DENY). The
+first registered range defines the global policy (global ALLOW if the first
+@action is DENY, global DENY if the first @action is ALLOW). Multiple ranges
+can be programmed, and must fit within the event space defined by the PMU
+architecture (10 bits on ARMv8.0, 16 bits from ARMv8.1 onwards).
+
+Note: "Cancelling" a filter by registering the opposite action for the same
+range doesn't change the default action. For example, installing an ALLOW
+filter for event range [0:10) as the first filter and then applying a DENY
+action for the same range will leave the whole range as disabled.
+
+Restrictions: Event 0 (SW_INCR) is never filtered, as it doesn't count a
+hardware event. Filtering event 0x1E (CHAIN) has no effect either, as it
+isn't strictly speaking an event. Filtering the cycle counter is possible
+using event 0x11 (CPU_CYCLES).
+
2. GROUP: KVM_ARM_VCPU_TIMER_CTRL
=================================