From 726b99c4f73c2e386c4ec5aa90d5124489573bd2 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 24 Aug 2017 20:51:35 +0200 Subject: KVM: x86: document special identity map address value MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Setting it to 0 leads to setting it to the default value, let's document this. Reviewed-by: Radim Krčmář Signed-off-by: David Hildenbrand Signed-off-by: Radim Krčmář --- Documentation/virtual/kvm/api.txt | 3 +++ 1 file changed, 3 insertions(+) (limited to 'Documentation') diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index e63a35fafef0..22bc5a052a5d 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1124,6 +1124,9 @@ guest physical address space and must not conflict with any memory slot or any mmio address. The guest may malfunction if it accesses this memory region. +Setting the address to 0 will result in resetting the address to its default +(0xfffbc000). + This ioctl is required on Intel-based hosts. This is needed on Intel hardware because of a quirk in the virtualization implementation (see the internals documentation when it pops into existence). -- cgit From 1af1ac910bb3394ac1c0062f5781983dde40a8c0 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Thu, 24 Aug 2017 20:51:36 +0200 Subject: KVM: x86: allow setting identity map addr with no vcpus only MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Changing it afterwards doesn't make too much sense and will only result in inconsistencies. Reviewed-by: Radim Krčmář Signed-off-by: David Hildenbrand Signed-off-by: Radim Krčmář --- Documentation/virtual/kvm/api.txt | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation') diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 22bc5a052a5d..dd2dd96927b8 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1131,6 +1131,7 @@ This ioctl is required on Intel-based hosts. This is needed on Intel hardware because of a quirk in the virtualization implementation (see the internals documentation when it pops into existence). +Fails if any VCPU has already been created. 4.41 KVM_SET_BOOT_CPU_ID -- cgit From ae204f80ca4074b6db07bd28c75faf02718735a0 Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Thu, 26 Oct 2017 17:23:10 +0200 Subject: KVM: arm/arm64: Document KVM_DEV_ARM_ITS_CTRL_RESET At the moment, the in-kernel emulated ITS is not properly reset. On guest restart/reset some registers keep their old values and internal structures like device, ITE, and collection lists are not freed. This may lead to various bugs. Among them, we can have incorrect state backup or failure when saving the ITS state at early guest boot stage. This patch documents a new attribute, KVM_DEV_ARM_ITS_CTRL_RESET in the KVM_DEV_ARM_VGIC_GRP_CTRL group. Upon this action, we can reset registers and especially those pointing to tables previously allocated by the guest and free the internal data structures storing the list of devices, collections and lpis. The usual approach for device reset of having userspace write the reset values of the registers to the kernel via the register read/write APIs doesn't work for the ITS because it has some internal state (caches) which is not exposed as registers, and there is no register interface for "drop cached data without writing it back to RAM". So we need a KVM API which mimics the hardware's reset line, to provide the equivalent behaviour to a "pull the power cord out of the back of the machine" reset. Reviewed-by: Christoffer Dall Reviewed-by: Marc Zyngier Signed-off-by: Eric Auger Reported-by: wanghaibin Signed-off-by: Christoffer Dall --- Documentation/virtual/kvm/devices/arm-vgic-its.txt | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'Documentation') diff --git a/Documentation/virtual/kvm/devices/arm-vgic-its.txt b/Documentation/virtual/kvm/devices/arm-vgic-its.txt index eb06beb75960..8d5830eab26a 100644 --- a/Documentation/virtual/kvm/devices/arm-vgic-its.txt +++ b/Documentation/virtual/kvm/devices/arm-vgic-its.txt @@ -33,6 +33,10 @@ Groups: request the initialization of the ITS, no additional parameter in kvm_device_attr.addr. + KVM_DEV_ARM_ITS_CTRL_RESET + reset the ITS, no additional parameter in kvm_device_attr.addr. + See "ITS Reset State" section. + KVM_DEV_ARM_ITS_SAVE_TABLES save the ITS table data into guest RAM, at the location provisioned by the guest in corresponding registers/table entries. @@ -157,3 +161,19 @@ Then vcpus can be started. - pINTID is the physical LPI ID; if zero, it means the entry is not valid and other fields are not meaningful. - ICID is the collection ID + + ITS Reset State: + ---------------- + +RESET returns the ITS to the same state that it was when first created and +initialized. When the RESET command returns, the following things are +guaranteed: + +- The ITS is not enabled and quiescent + GITS_CTLR.Enabled = 0 .Quiescent=1 +- There is no internally cached state +- No collection or device table are used + GITS_BASER.Valid = 0 +- GITS_CBASER = 0, GITS_CREADR = 0, GITS_CWRITER = 0 +- The ABI version is unchanged and remains the one set when the ITS + device was first created. -- cgit From 4dd6f17eb913d3d23dd6c07950627ac2c3068dca Mon Sep 17 00:00:00 2001 From: Michael Mueller Date: Thu, 6 Jul 2017 14:22:20 +0200 Subject: KVM: s390: clear_io_irq() requests are not expected for adapter interrupts There is a chance to delete not yet delivered I/O interrupts if an exploiter uses the subsystem identification word 0x0000 while processing a KVM_DEV_FLIC_CLEAR_IO_IRQ ioctl. -EINVAL will be returned now instead in that case. Classic interrupts will always have bit 0x10000 set in the schid while adapter interrupts have a zero schid. The clear_io_irq interface is only useful for classic interrupts (as adapter interrupts belong to many devices). Let's make this interface more strict and forbid a schid of 0. Signed-off-by: Michael Mueller Reviewed-by: Halil Pasic Reviewed-by: Christian Borntraeger Reviewed-by: Cornelia Huck Signed-off-by: Christian Borntraeger --- Documentation/virtual/kvm/devices/s390_flic.txt | 3 +++ 1 file changed, 3 insertions(+) (limited to 'Documentation') diff --git a/Documentation/virtual/kvm/devices/s390_flic.txt b/Documentation/virtual/kvm/devices/s390_flic.txt index 2f1cbf1301d2..27ad53c7149d 100644 --- a/Documentation/virtual/kvm/devices/s390_flic.txt +++ b/Documentation/virtual/kvm/devices/s390_flic.txt @@ -156,3 +156,6 @@ FLIC with an unknown group or attribute gives the error code EINVAL (instead of ENXIO, as specified in the API documentation). It is not possible to conclude that a FLIC operation is unavailable based on the error code resulting from a usage attempt. + +Note: The KVM_DEV_FLIC_CLEAR_IO_IRQ ioctl will return EINVAL in case a zero +schid is specified. -- cgit From da9a1446d248f673a8560ce46251ff620214ab7b Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Thu, 9 Nov 2017 10:00:45 +0100 Subject: KVM: s390: provide a capability for AIS state migration The AIS capability was introduced in 4.12, while the interface to migrate the state was added in 4.13. Unfortunately it is not possible for userspace to detect the migration capability without creating a flic kvm device. As in QEMU the cpu model detection runs on the "none" machine this will result in cpu model issues regarding the "ais" capability. To get the "ais" capability properly let's add a new KVM capability that tells userspace that AIS states can be migrated. Signed-off-by: Christian Borntraeger Reviewed-by: Cornelia Huck Reviewed-by: David Hildenbrand Acked-by: Halil Pasic --- Documentation/virtual/kvm/api.txt | 9 +++++++++ Documentation/virtual/kvm/devices/s390_flic.txt | 2 ++ 2 files changed, 11 insertions(+) (limited to 'Documentation') diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index e63a35fafef0..49540e53c4bd 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -4347,3 +4347,12 @@ This capability indicates that userspace can load HV_X64_MSR_VP_INDEX msr. Its value is used to denote the target vcpu for a SynIC interrupt. For compatibilty, KVM initializes this msr to KVM's internal vcpu index. When this capability is absent, userspace can still query this msr's value. + +8.13 KVM_CAP_S390_AIS_MIGRATION + +Architectures: s390 +Parameters: none + +This capability indicates if the flic device will be able to get/set the +AIS states for migration via the KVM_DEV_FLIC_AISM_ALL attribute and allows +to discover this without having to create a flic device. diff --git a/Documentation/virtual/kvm/devices/s390_flic.txt b/Documentation/virtual/kvm/devices/s390_flic.txt index 27ad53c7149d..a4e20a090174 100644 --- a/Documentation/virtual/kvm/devices/s390_flic.txt +++ b/Documentation/virtual/kvm/devices/s390_flic.txt @@ -151,6 +151,8 @@ struct kvm_s390_ais_all { to an ISC (MSB0 bit 0 to ISC 0 and so on). The combination of simm bit and nimm bit presents AIS mode for a ISC. + KVM_DEV_FLIC_AISM_ALL is indicated by KVM_CAP_S390_AIS_MIGRATION. + Note: The KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR device ioctls executed on FLIC with an unknown group or attribute gives the error code EINVAL (instead of ENXIO, as specified in the API documentation). It is not possible to conclude -- cgit