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-rw-r--r--Documentation/virtual/kvm/api.txt179
1 files changed, 171 insertions, 8 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 42542eb802c..13ab8379b4e 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -180,6 +180,19 @@ KVM_CHECK_EXTENSION ioctl() to determine the value for max_vcpus at run-time.
180If the KVM_CAP_NR_VCPUS does not exist, you should assume that max_vcpus is 4 180If the KVM_CAP_NR_VCPUS does not exist, you should assume that max_vcpus is 4
181cpus max. 181cpus max.
182 182
183On powerpc using book3s_hv mode, the vcpus are mapped onto virtual
184threads in one or more virtual CPU cores. (This is because the
185hardware requires all the hardware threads in a CPU core to be in the
186same partition.) The KVM_CAP_PPC_SMT capability indicates the number
187of vcpus per virtual core (vcore). The vcore id is obtained by
188dividing the vcpu id by the number of vcpus per vcore. The vcpus in a
189given vcore will always be in the same physical core as each other
190(though that might be a different physical core from time to time).
191Userspace can control the threading (SMT) mode of the guest by its
192allocation of vcpu ids. For example, if userspace wants
193single-threaded guest vcpus, it should make all vcpu ids be a multiple
194of the number of vcpus per vcore.
195
1834.8 KVM_GET_DIRTY_LOG (vm ioctl) 1964.8 KVM_GET_DIRTY_LOG (vm ioctl)
184 197
185Capability: basic 198Capability: basic
@@ -1118,6 +1131,13 @@ following flags are specified:
1118/* Depends on KVM_CAP_IOMMU */ 1131/* Depends on KVM_CAP_IOMMU */
1119#define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0) 1132#define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0)
1120 1133
1134The KVM_DEV_ASSIGN_ENABLE_IOMMU flag is a mandatory option to ensure
1135isolation of the device. Usages not specifying this flag are deprecated.
1136
1137Only PCI header type 0 devices with PCI BAR resources are supported by
1138device assignment. The user requesting this ioctl must have read/write
1139access to the PCI sysfs resource files associated with the device.
1140
11214.49 KVM_DEASSIGN_PCI_DEVICE 11414.49 KVM_DEASSIGN_PCI_DEVICE
1122 1142
1123Capability: KVM_CAP_DEVICE_DEASSIGNMENT 1143Capability: KVM_CAP_DEVICE_DEASSIGNMENT
@@ -1143,15 +1163,10 @@ Assigns an IRQ to a passed-through device.
1143 1163
1144struct kvm_assigned_irq { 1164struct kvm_assigned_irq {
1145 __u32 assigned_dev_id; 1165 __u32 assigned_dev_id;
1146 __u32 host_irq; 1166 __u32 host_irq; /* ignored (legacy field) */
1147 __u32 guest_irq; 1167 __u32 guest_irq;
1148 __u32 flags; 1168 __u32 flags;
1149 union { 1169 union {
1150 struct {
1151 __u32 addr_lo;
1152 __u32 addr_hi;
1153 __u32 data;
1154 } guest_msi;
1155 __u32 reserved[12]; 1170 __u32 reserved[12];
1156 }; 1171 };
1157}; 1172};
@@ -1239,8 +1254,10 @@ Type: vm ioctl
1239Parameters: struct kvm_assigned_msix_nr (in) 1254Parameters: struct kvm_assigned_msix_nr (in)
1240Returns: 0 on success, -1 on error 1255Returns: 0 on success, -1 on error
1241 1256
1242Set the number of MSI-X interrupts for an assigned device. This service can 1257Set the number of MSI-X interrupts for an assigned device. The number is
1243only be called once in the lifetime of an assigned device. 1258reset again by terminating the MSI-X assignment of the device via
1259KVM_DEASSIGN_DEV_IRQ. Calling this service more than once at any earlier
1260point will fail.
1244 1261
1245struct kvm_assigned_msix_nr { 1262struct kvm_assigned_msix_nr {
1246 __u32 assigned_dev_id; 1263 __u32 assigned_dev_id;
@@ -1291,6 +1308,135 @@ Returns the tsc frequency of the guest. The unit of the return value is
1291KHz. If the host has unstable tsc this ioctl returns -EIO instead as an 1308KHz. If the host has unstable tsc this ioctl returns -EIO instead as an
1292error. 1309error.
1293 1310
13114.56 KVM_GET_LAPIC
1312
1313Capability: KVM_CAP_IRQCHIP
1314Architectures: x86
1315Type: vcpu ioctl
1316Parameters: struct kvm_lapic_state (out)
1317Returns: 0 on success, -1 on error
1318
1319#define KVM_APIC_REG_SIZE 0x400
1320struct kvm_lapic_state {
1321 char regs[KVM_APIC_REG_SIZE];
1322};
1323
1324Reads the Local APIC registers and copies them into the input argument. The
1325data format and layout are the same as documented in the architecture manual.
1326
13274.57 KVM_SET_LAPIC
1328
1329Capability: KVM_CAP_IRQCHIP
1330Architectures: x86
1331Type: vcpu ioctl
1332Parameters: struct kvm_lapic_state (in)
1333Returns: 0 on success, -1 on error
1334
1335#define KVM_APIC_REG_SIZE 0x400
1336struct kvm_lapic_state {
1337 char regs[KVM_APIC_REG_SIZE];
1338};
1339
1340Copies the input argument into the the Local APIC registers. The data format
1341and layout are the same as documented in the architecture manual.
1342
13434.58 KVM_IOEVENTFD
1344
1345Capability: KVM_CAP_IOEVENTFD
1346Architectures: all
1347Type: vm ioctl
1348Parameters: struct kvm_ioeventfd (in)
1349Returns: 0 on success, !0 on error
1350
1351This ioctl attaches or detaches an ioeventfd to a legal pio/mmio address
1352within the guest. A guest write in the registered address will signal the
1353provided event instead of triggering an exit.
1354
1355struct kvm_ioeventfd {
1356 __u64 datamatch;
1357 __u64 addr; /* legal pio/mmio address */
1358 __u32 len; /* 1, 2, 4, or 8 bytes */
1359 __s32 fd;
1360 __u32 flags;
1361 __u8 pad[36];
1362};
1363
1364The following flags are defined:
1365
1366#define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch)
1367#define KVM_IOEVENTFD_FLAG_PIO (1 << kvm_ioeventfd_flag_nr_pio)
1368#define KVM_IOEVENTFD_FLAG_DEASSIGN (1 << kvm_ioeventfd_flag_nr_deassign)
1369
1370If datamatch flag is set, the event will be signaled only if the written value
1371to the registered address is equal to datamatch in struct kvm_ioeventfd.
1372
13734.62 KVM_CREATE_SPAPR_TCE
1374
1375Capability: KVM_CAP_SPAPR_TCE
1376Architectures: powerpc
1377Type: vm ioctl
1378Parameters: struct kvm_create_spapr_tce (in)
1379Returns: file descriptor for manipulating the created TCE table
1380
1381This creates a virtual TCE (translation control entry) table, which
1382is an IOMMU for PAPR-style virtual I/O. It is used to translate
1383logical addresses used in virtual I/O into guest physical addresses,
1384and provides a scatter/gather capability for PAPR virtual I/O.
1385
1386/* for KVM_CAP_SPAPR_TCE */
1387struct kvm_create_spapr_tce {
1388 __u64 liobn;
1389 __u32 window_size;
1390};
1391
1392The liobn field gives the logical IO bus number for which to create a
1393TCE table. The window_size field specifies the size of the DMA window
1394which this TCE table will translate - the table will contain one 64
1395bit TCE entry for every 4kiB of the DMA window.
1396
1397When the guest issues an H_PUT_TCE hcall on a liobn for which a TCE
1398table has been created using this ioctl(), the kernel will handle it
1399in real mode, updating the TCE table. H_PUT_TCE calls for other
1400liobns will cause a vm exit and must be handled by userspace.
1401
1402The return value is a file descriptor which can be passed to mmap(2)
1403to map the created TCE table into userspace. This lets userspace read
1404the entries written by kernel-handled H_PUT_TCE calls, and also lets
1405userspace update the TCE table directly which is useful in some
1406circumstances.
1407
14084.63 KVM_ALLOCATE_RMA
1409
1410Capability: KVM_CAP_PPC_RMA
1411Architectures: powerpc
1412Type: vm ioctl
1413Parameters: struct kvm_allocate_rma (out)
1414Returns: file descriptor for mapping the allocated RMA
1415
1416This allocates a Real Mode Area (RMA) from the pool allocated at boot
1417time by the kernel. An RMA is a physically-contiguous, aligned region
1418of memory used on older POWER processors to provide the memory which
1419will be accessed by real-mode (MMU off) accesses in a KVM guest.
1420POWER processors support a set of sizes for the RMA that usually
1421includes 64MB, 128MB, 256MB and some larger powers of two.
1422
1423/* for KVM_ALLOCATE_RMA */
1424struct kvm_allocate_rma {
1425 __u64 rma_size;
1426};
1427
1428The return value is a file descriptor which can be passed to mmap(2)
1429to map the allocated RMA into userspace. The mapped area can then be
1430passed to the KVM_SET_USER_MEMORY_REGION ioctl to establish it as the
1431RMA for a virtual machine. The size of the RMA in bytes (which is
1432fixed at host kernel boot time) is returned in the rma_size field of
1433the argument structure.
1434
1435The KVM_CAP_PPC_RMA capability is 1 or 2 if the KVM_ALLOCATE_RMA ioctl
1436is supported; 2 if the processor requires all virtual machines to have
1437an RMA, or 1 if the processor can use an RMA but doesn't require it,
1438because it supports the Virtual RMA (VRMA) facility.
1439
12945. The kvm_run structure 14405. The kvm_run structure
1295 1441
1296Application code obtains a pointer to the kvm_run structure by 1442Application code obtains a pointer to the kvm_run structure by
@@ -1473,6 +1619,23 @@ Userspace can now handle the hypercall and when it's done modify the gprs as
1473necessary. Upon guest entry all guest GPRs will then be replaced by the values 1619necessary. Upon guest entry all guest GPRs will then be replaced by the values
1474in this struct. 1620in this struct.
1475 1621
1622 /* KVM_EXIT_PAPR_HCALL */
1623 struct {
1624 __u64 nr;
1625 __u64 ret;
1626 __u64 args[9];
1627 } papr_hcall;
1628
1629This is used on 64-bit PowerPC when emulating a pSeries partition,
1630e.g. with the 'pseries' machine type in qemu. It occurs when the
1631guest does a hypercall using the 'sc 1' instruction. The 'nr' field
1632contains the hypercall number (from the guest R3), and 'args' contains
1633the arguments (from the guest R4 - R12). Userspace should put the
1634return code in 'ret' and any extra returned values in args[].
1635The possible hypercalls are defined in the Power Architecture Platform
1636Requirements (PAPR) document available from www.power.org (free
1637developer registration required to access it).
1638
1476 /* Fix the size of the union. */ 1639 /* Fix the size of the union. */
1477 char padding[256]; 1640 char padding[256];
1478 }; 1641 };