Public bug reported: UuidCreateSequential() usually creates version 1 UUIDs (1) which means they contain the main network card's MAC address. However when using a virtio network card and driver the UUIDs contain random data instead of the guest's MAC address. Changing the network card to either the default rtl8139 one or the e1000 one fixes the issue.
Here is the software I have tested this with: * qemu 1.1.2+dfsg-5 and 1.4.0~rc0+dfsg-1exp (from Debian Testing and Experimental respectively) * The 0.1-49 and 0.1-52 Windows virtio drivers from https://alt.fedoraproject.org/pub/alt/virtio-win/latest/images/bin/ * Both a 32-bit Windows XP guest and a 64-bit Windows 7 one. Here is how to test for this issue: * Set up a Windows guest with a single network card(2), a virtio one and install the corresponding driver. * Boot the guest and copy the uuidtest.exe file (see attachement) to it * On the command line, type 'ipconfig /all'. Give you the correct network card's MAC address on a line like the one below: Physical Address. . . . . . . . . : 52-54-00-C7-0E-97 * Run uuidtest.exe. It will show the VM returning a UUID with the wrong MAC address, and quite possibly even a multicast MAC address! (3). In the example below 'f75292c62787' should have been the MAC address. Note that on Windows XP UuidCreateSequential() returns RPC_S_UUID_LOCAL_ONLY for virtio cards but that on Windows 7 it returns 0. UuidCreateSequential() returned 0 uuid={56e1ffe4-71d8-11e2-b1cc-f75292c62787} Got a version 1 UUID The UUID does not contain a non-multicast MAC address * Reboot and notice uuidtest.exe now reports a different value where the MAC address should be. * Shut down the VM and switch the network card to rtl8139, install the drivers, run uuidtest.exe and notice that the last group of digits finally contains the correct MAC address. (1) https://en.wikipedia.org/wiki/Globally_unique_identifier#Algorithm (2) Best do it with a single card to avoid confusion over which is the primary one. (3) If the first byte of the address is odd then this is a multicast address. https://en.wikipedia.org/wiki/MAC_address#Address_details ** Affects: qemu Importance: Undecided Status: New ** Attachment added: "Test executable and source" https://bugs.launchpad.net/bugs/1119281/+attachment/3520477/+files/uuidtest.tar.bz2 -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1119281 Title: The virtio network device breaks UuidCreateSequential() Status in QEMU: New Bug description: UuidCreateSequential() usually creates version 1 UUIDs (1) which means they contain the main network card's MAC address. However when using a virtio network card and driver the UUIDs contain random data instead of the guest's MAC address. Changing the network card to either the default rtl8139 one or the e1000 one fixes the issue. Here is the software I have tested this with: * qemu 1.1.2+dfsg-5 and 1.4.0~rc0+dfsg-1exp (from Debian Testing and Experimental respectively) * The 0.1-49 and 0.1-52 Windows virtio drivers from https://alt.fedoraproject.org/pub/alt/virtio-win/latest/images/bin/ * Both a 32-bit Windows XP guest and a 64-bit Windows 7 one. Here is how to test for this issue: * Set up a Windows guest with a single network card(2), a virtio one and install the corresponding driver. * Boot the guest and copy the uuidtest.exe file (see attachement) to it * On the command line, type 'ipconfig /all'. Give you the correct network card's MAC address on a line like the one below: Physical Address. . . . . . . . . : 52-54-00-C7-0E-97 * Run uuidtest.exe. It will show the VM returning a UUID with the wrong MAC address, and quite possibly even a multicast MAC address! (3). In the example below 'f75292c62787' should have been the MAC address. Note that on Windows XP UuidCreateSequential() returns RPC_S_UUID_LOCAL_ONLY for virtio cards but that on Windows 7 it returns 0. UuidCreateSequential() returned 0 uuid={56e1ffe4-71d8-11e2-b1cc-f75292c62787} Got a version 1 UUID The UUID does not contain a non-multicast MAC address * Reboot and notice uuidtest.exe now reports a different value where the MAC address should be. * Shut down the VM and switch the network card to rtl8139, install the drivers, run uuidtest.exe and notice that the last group of digits finally contains the correct MAC address. (1) https://en.wikipedia.org/wiki/Globally_unique_identifier#Algorithm (2) Best do it with a single card to avoid confusion over which is the primary one. (3) If the first byte of the address is odd then this is a multicast address. https://en.wikipedia.org/wiki/MAC_address#Address_details To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1119281/+subscriptions
