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authorDongjiu Geng <gengdongjiu@huawei.com>2018-07-19 16:24:23 +0100
committerMarc Zyngier <marc.zyngier@arm.com>2018-07-21 16:02:31 +0100
commitbe26b3a73413c2ebf14d5e76a66ad964e6458080 (patch)
tree1873d5e6cfeeff600bd96bab25418c291ac25ecf /Documentation/virtual
parentb7b27facc7b50a5fce0afaa3df56157136ce181a (diff)
downloadlinux-be26b3a73413c2ebf14d5e76a66ad964e6458080.tar.bz2
arm64: KVM: export the capability to set guest SError syndrome
For the arm64 RAS Extension, user space can inject a virtual-SError with specified ESR. So user space needs to know whether KVM support to inject such SError, this interface adds this query for this capability. KVM will check whether system support RAS Extension, if supported, KVM returns true to user space, otherwise returns false. Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com> Reviewed-by: James Morse <james.morse@arm.com> [expanded documentation wording] Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'Documentation/virtual')
-rw-r--r--Documentation/virtual/kvm/api.txt26
1 files changed, 26 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 284d36e72f28..dbbb95d5798a 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -907,6 +907,18 @@ SError is pending, the architecture's 'Multiple SError interrupts' rules should
be followed. (2.5.3 of DDI0587.a "ARM Reliability, Availability, and
Serviceability (RAS) Specification").
+SError exceptions always have an ESR value. Some CPUs have the ability to
+specify what the virtual SError's ESR value should be. These systems will
+advertise KVM_CAP_ARM_SET_SERROR_ESR. In this case exception.has_esr will
+always have a non-zero value when read, and the agent making an SError pending
+should specify the ISS field in the lower 24 bits of exception.serror_esr. If
+the system supports KVM_CAP_ARM_SET_SERROR_ESR, but user-space sets the events
+with exception.has_esr as zero, KVM will choose an ESR.
+
+Specifying exception.has_esr on a system that does not support it will return
+-EINVAL. Setting anything other than the lower 24bits of exception.serror_esr
+will return -EINVAL.
+
struct kvm_vcpu_events {
struct {
__u8 serror_pending;
@@ -4664,3 +4676,17 @@ This capability indicates that KVM supports paravirtualized Hyper-V TLB Flush
hypercalls:
HvFlushVirtualAddressSpace, HvFlushVirtualAddressSpaceEx,
HvFlushVirtualAddressList, HvFlushVirtualAddressListEx.
+
+8.19 KVM_CAP_ARM_SET_SERROR_ESR
+
+Architectures: arm, arm64
+
+This capability indicates that userspace can specify (via the
+KVM_SET_VCPU_EVENTS ioctl) the syndrome value reported to the guest when it
+takes a virtual SError interrupt exception.
+If KVM advertises this capability, userspace can only specify the ISS field for
+the ESR syndrome. Other parts of the ESR, such as the EC are generated by the
+CPU when the exception is taken. If this virtual SError is taken to EL1 using
+AArch64, this value will be reported in the ISS field of ESR_ELx.
+
+See KVM_CAP_VCPU_EVENTS for more details.