[libvirt] [libvirt-java] [PATCH 52/65] Implement Domain.memoryPeek

This wraps the virDomainMemoryPeek libvirt function, available since version 0.4.5. Signed-off-by: Claudio Bley <cbley(a)av-test.de&gt; --- src/main/java/org/libvirt/Domain.java | 40 ++++++++++++++++++++++ src/main/java/org/libvirt/MemoryAddressMode.java | 19 ++++++++++ src/main/java/org/libvirt/jna/Libvirt.java | 5 +-- 3 files changed, 60 insertions(+), 4 deletions(-) create mode 100644 src/main/java/org/libvirt/MemoryAddressMode.java diff --git a/src/main/java/org/libvirt/Domain.java b/src/main/java/org/libvirt/Domain.java index f57460f..5f0d1d0 100644 --- a/src/main/java/org/libvirt/Domain.java +++ b/src/main/java/org/libvirt/Domain.java @@ -826,6 +826,46 @@ public class Domain { } /** + * Read the contents of a domain's memory. + * <p> + * If mode is MemoryAddressMode.VIRTUAL the 'start' parameter is + * interpreted as virtual memory address for whichever task + * happens to be running on the domain at the moment. Although + * this sounds haphazard it is in fact what you want in order to + * read Linux kernel state, because it ensures that pointers in + * the kernel image can be interpreted coherently. + * <p> + * This method always reads the number of bytes remaining in the + * buffer, that is, {@code buffer.remaining()} at the moment this + * method is invoked. Upon return the buffer's position will be + * equal to the limit, the limit itself will not have changed. + * + * @param start the start address of the memory to peek + * @param mode the mode which determines whether the given addresses + * are interpreted as virtual or physical addresses + */ + public void memoryPeek(long start, ByteBuffer buffer, MemoryAddressMode mode) throws LibvirtException + { + SizeT size = new SizeT(); + + // older libvirt has a limitation on the size of data + // transferred per request in the remote driver. So, split + // larger requests into 64K blocks. + + do { + final int req = Math.min(65536, buffer.remaining()); + + size.setValue(req); + + processError(libvirt.virDomainMemoryPeek(this.VDP, start, size, buffer, mode.getValue())); + + buffer.position(buffer.position() + req); + } while (buffer.hasRemaining()); + + assert buffer.position() == buffer.limit(); + } + + /** * This function provides memory statistics for the domain. * * @param number diff --git a/src/main/java/org/libvirt/MemoryAddressMode.java b/src/main/java/org/libvirt/MemoryAddressMode.java new file mode 100644 index 0000000..c16edea --- /dev/null +++ b/src/main/java/org/libvirt/MemoryAddressMode.java @@ -0,0 +1,19 @@ +package org.libvirt; + +public enum MemoryAddressMode { + /** addresses are virtual addresses */ + VIRTUAL(1), + + /** addresses are physical addresses */ + PHYSICAL(2); + + private final int value; + + MemoryAddressMode(int v) { + this.value = v; + } + + int getValue() { + return value; + } +} diff --git a/src/main/java/org/libvirt/jna/Libvirt.java b/src/main/java/org/libvirt/jna/Libvirt.java index 0452246..28fbff1 100644 --- a/src/main/java/org/libvirt/jna/Libvirt.java +++ b/src/main/java/org/libvirt/jna/Libvirt.java @@ -22,10 +22,6 @@ import com.sun.jna.ptr.PointerByReference; * virConnCopyLastError * virFreeError * - * LIBVIRT_0.4.2 - * virDomainBlockPeek - * virDomainMemoryPeek - * * LIBVIRT_0_5.0 * virEventRegisterImpl * virConnectDomainEventRegister @@ -286,6 +282,7 @@ public interface Libvirt extends Library { DomainPointer virDomainLookupByUUIDString(ConnectionPointer virConnectPtr, String uuidstr); int virDomainManagedSave(DomainPointer virDomainPtr, int flags); int virDomainManagedSaveRemove(DomainPointer virDomainPtr, int flags); + int virDomainMemoryPeek(DomainPointer virDomainPtr, long start, SizeT size, ByteBuffer buffer, int flags); DomainPointer virDomainMigrate(DomainPointer virDomainPtr, ConnectionPointer virConnectPtr, NativeLong flags, String dname, String uri, NativeLong bandwidth); DomainPointer virDomainMigrate2(DomainPointer virDomainPtr, ConnectionPointer virConnectPtr, -- 1.7.9.5