* [Qemu-devel] How to generate custom fw paths for IDE devices? @ 2018-07-18 21:13 Mark Cave-Ayland 2018-07-19 8:10 ` Thomas Huth ` (2 more replies) 0 siblings, 3 replies; 10+ messages in thread From: Mark Cave-Ayland @ 2018-07-18 21:13 UTC (permalink / raw) To: qemu-devel; +Cc: qemu-block, jsnow, Kevin Wolf, armbru, marcel, Laszlo Ersek Hi all, Following on from a couple of patches I've previously posted to the mailing list at https://lists.gnu.org/archive/html/qemu-devel/2018-06/msg08836.html I've made some good progress with trying to add bootindex support to OpenBIOS but I'm stuck with generating the IDE device paths from QEMU. According to OpenBIOS the device path for a cdrom on a sun4u machine should be: /pci@1fe,0/pci@1,1/ide@3/ide1@8100/cdrom@0 whereas with my working patchset I'm currently generating: /pci@1fe,0/pci@1,1/ide@3/drive@1 The issue is that the drive@1 part is being generated by the IDE drive device attached to the IDE bus in hw/ide/qdev.c, and so I think I need to override idebus_get_fw_dev_path() to manually generate the remainder of the path including both the controller and the correctly named drive node. One option may be to consider subclassing IDEBus and overriding idebus_get_fw_dev_path() there, but the cmd646 device is a child of TYPE_PCI_IDE which has its own internal IDEBus and so it seems overriding it is impossible. Can anyone point me in the right direction as to how to generate the correct fw path for IDE devices in the above format for sun4u machines? ATB, Mark. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Qemu-devel] How to generate custom fw paths for IDE devices? 2018-07-18 21:13 [Qemu-devel] How to generate custom fw paths for IDE devices? Mark Cave-Ayland @ 2018-07-19 8:10 ` Thomas Huth 2018-07-19 16:46 ` Mark Cave-Ayland 2018-07-19 8:29 ` Laszlo Ersek 2018-07-25 13:03 ` [Qemu-devel] [Qemu-block] " Paolo Bonzini 2 siblings, 1 reply; 10+ messages in thread From: Thomas Huth @ 2018-07-19 8:10 UTC (permalink / raw) To: Mark Cave-Ayland, qemu-devel Cc: Kevin Wolf, qemu-block, Laszlo Ersek, armbru, marcel, jsnow, qemu-ppc On 18.07.2018 23:13, Mark Cave-Ayland wrote: > Hi all, > > Following on from a couple of patches I've previously posted to the > mailing list at > https://lists.gnu.org/archive/html/qemu-devel/2018-06/msg08836.html I've > made some good progress with trying to add bootindex support to OpenBIOS > but I'm stuck with generating the IDE device paths from QEMU. > > According to OpenBIOS the device path for a cdrom on a sun4u machine > should be: > > /pci@1fe,0/pci@1,1/ide@3/ide1@8100/cdrom@0 > > whereas with my working patchset I'm currently generating: > > /pci@1fe,0/pci@1,1/ide@3/drive@1 > > The issue is that the drive@1 part is being generated by the IDE drive > device attached to the IDE bus in hw/ide/qdev.c, and so I think I need > to override idebus_get_fw_dev_path() to manually generate the remainder > of the path including both the controller and the correctly named drive > node. > > One option may be to consider subclassing IDEBus and overriding > idebus_get_fw_dev_path() there, but the cmd646 device is a child of > TYPE_PCI_IDE which has its own internal IDEBus and so it seems > overriding it is impossible. > > Can anyone point me in the right direction as to how to generate the > correct fw path for IDE devices in the above format for sun4u machines? Not sure if it is of any help, but the pseries machine is also rewriting the device paths for the device tree: See function spapr_get_fw_dev_path in hw/ppc/spapr.c. Thomas ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Qemu-devel] How to generate custom fw paths for IDE devices? 2018-07-19 8:10 ` Thomas Huth @ 2018-07-19 16:46 ` Mark Cave-Ayland 0 siblings, 0 replies; 10+ messages in thread From: Mark Cave-Ayland @ 2018-07-19 16:46 UTC (permalink / raw) To: Thomas Huth, qemu-devel Cc: Kevin Wolf, qemu-block, Laszlo Ersek, armbru, qemu-ppc, marcel, jsnow On 19/07/18 09:10, Thomas Huth wrote: > On 18.07.2018 23:13, Mark Cave-Ayland wrote: >> Hi all, >> >> Following on from a couple of patches I've previously posted to the >> mailing list at >> https://lists.gnu.org/archive/html/qemu-devel/2018-06/msg08836.html I've >> made some good progress with trying to add bootindex support to OpenBIOS >> but I'm stuck with generating the IDE device paths from QEMU. >> >> According to OpenBIOS the device path for a cdrom on a sun4u machine >> should be: >> >> /pci@1fe,0/pci@1,1/ide@3/ide1@8100/cdrom@0 >> >> whereas with my working patchset I'm currently generating: >> >> /pci@1fe,0/pci@1,1/ide@3/drive@1 >> >> The issue is that the drive@1 part is being generated by the IDE drive >> device attached to the IDE bus in hw/ide/qdev.c, and so I think I need >> to override idebus_get_fw_dev_path() to manually generate the remainder >> of the path including both the controller and the correctly named drive >> node. >> >> One option may be to consider subclassing IDEBus and overriding >> idebus_get_fw_dev_path() there, but the cmd646 device is a child of >> TYPE_PCI_IDE which has its own internal IDEBus and so it seems >> overriding it is impossible. >> >> Can anyone point me in the right direction as to how to generate the >> correct fw path for IDE devices in the above format for sun4u machines? > > Not sure if it is of any help, but the pseries machine is also rewriting > the device paths for the device tree: See function spapr_get_fw_dev_path > in hw/ppc/spapr.c. Ah I see - this is very useful indeed, as it seemingly allows all the fw paths to be managed in a single place without having to add Bus support. Thanks for the reference! ATB, Mark. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Qemu-devel] How to generate custom fw paths for IDE devices? 2018-07-18 21:13 [Qemu-devel] How to generate custom fw paths for IDE devices? Mark Cave-Ayland 2018-07-19 8:10 ` Thomas Huth @ 2018-07-19 8:29 ` Laszlo Ersek 2018-07-19 17:19 ` Mark Cave-Ayland 2018-07-25 13:03 ` [Qemu-devel] [Qemu-block] " Paolo Bonzini 2 siblings, 1 reply; 10+ messages in thread From: Laszlo Ersek @ 2018-07-19 8:29 UTC (permalink / raw) To: Mark Cave-Ayland, qemu-devel Cc: qemu-block, jsnow, Kevin Wolf, armbru, Marcel Apfelbaum (GMail address) (updating Marcel's address to his GMail one) On 07/18/18 23:13, Mark Cave-Ayland wrote: > Hi all, > > Following on from a couple of patches I've previously posted to the > mailing list at > https://lists.gnu.org/archive/html/qemu-devel/2018-06/msg08836.html I've > made some good progress with trying to add bootindex support to OpenBIOS > but I'm stuck with generating the IDE device paths from QEMU. > > According to OpenBIOS the device path for a cdrom on a sun4u machine > should be: > > /pci@1fe,0/pci@1,1/ide@3/ide1@8100/cdrom@0 > > whereas with my working patchset I'm currently generating: > > /pci@1fe,0/pci@1,1/ide@3/drive@1 > > The issue is that the drive@1 part is being generated by the IDE drive > device attached to the IDE bus in hw/ide/qdev.c, and so I think I need > to override idebus_get_fw_dev_path() to manually generate the remainder > of the path including both the controller and the correctly named drive > node. > > One option may be to consider subclassing IDEBus and overriding > idebus_get_fw_dev_path() there, but the cmd646 device is a child of > TYPE_PCI_IDE which has its own internal IDEBus and so it seems > overriding it is impossible. > > Can anyone point me in the right direction as to how to generate the > correct fw path for IDE devices in the above format for sun4u machines? What prevents you from recognizing, in the guest firmware, the OpenFirmware device path that is currently generated by QEMU? I mean, the device path generated by QEMU looks technically correct; it reflects how the IDE controller sits in a PCI B/D/F, and how the IDE drive sits on an IDE controller. Or do you actually have an intermediate IDE controller (at "address 0x8100" on the top IDE controller) in the sun4u machine type? Is the address 0x8100 actually needed by the firmware? If so, perhaps you could turn that intermediate IDE controller ("internal IDEBus") into its own class, and chain the instance of that class like the rest of the bus controllers are chained. (Just speculating...) Thanks Laszlo ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Qemu-devel] How to generate custom fw paths for IDE devices? 2018-07-19 8:29 ` Laszlo Ersek @ 2018-07-19 17:19 ` Mark Cave-Ayland 2018-07-19 19:03 ` Laszlo Ersek 0 siblings, 1 reply; 10+ messages in thread From: Mark Cave-Ayland @ 2018-07-19 17:19 UTC (permalink / raw) To: Laszlo Ersek, qemu-devel; +Cc: Kevin Wolf, jsnow, armbru, qemu-block On 19/07/18 09:29, Laszlo Ersek wrote: > (updating Marcel's address to his GMail one) > > On 07/18/18 23:13, Mark Cave-Ayland wrote: >> Hi all, >> >> Following on from a couple of patches I've previously posted to the >> mailing list at >> https://lists.gnu.org/archive/html/qemu-devel/2018-06/msg08836.html I've >> made some good progress with trying to add bootindex support to OpenBIOS >> but I'm stuck with generating the IDE device paths from QEMU. >> >> According to OpenBIOS the device path for a cdrom on a sun4u machine >> should be: >> >> /pci@1fe,0/pci@1,1/ide@3/ide1@8100/cdrom@0 >> >> whereas with my working patchset I'm currently generating: >> >> /pci@1fe,0/pci@1,1/ide@3/drive@1 >> >> The issue is that the drive@1 part is being generated by the IDE drive >> device attached to the IDE bus in hw/ide/qdev.c, and so I think I need >> to override idebus_get_fw_dev_path() to manually generate the remainder >> of the path including both the controller and the correctly named drive >> node. >> >> One option may be to consider subclassing IDEBus and overriding >> idebus_get_fw_dev_path() there, but the cmd646 device is a child of >> TYPE_PCI_IDE which has its own internal IDEBus and so it seems >> overriding it is impossible. >> >> Can anyone point me in the right direction as to how to generate the >> correct fw path for IDE devices in the above format for sun4u machines? > > What prevents you from recognizing, in the guest firmware, the > OpenFirmware device path that is currently generated by QEMU? In a word: compatibility. With the older SPARC/PPC machines the OSs are *very* picky about device names and often make assumptions about the DT layout instead of parsing it properly, simply because at that time no-one really thought of running the software on anything but a real machine. > I mean, the device path generated by QEMU looks technically correct; it > reflects how the IDE controller sits in a PCI B/D/F, and how the IDE > drive sits on an IDE controller. Or do you actually have an intermediate > IDE controller (at "address 0x8100" on the top IDE controller) in the > sun4u machine type? Is the address 0x8100 actually needed by the firmware? > > If so, perhaps you could turn that intermediate IDE controller > ("internal IDEBus") into its own class, and chain the instance of that > class like the rest of the bus controllers are chained. (Just > speculating...) In the case of the IDE device, the devices represent the primary/secondary interfaces and not the separate controllers: the primary lives at 0x8000 and the secondary at 0x8100. The other problem with changing this is that currently as there is no bootindex support, these map to the legacy -hda and -cdrom options correctly so even if I could do this, and even if all the OSs would still parse the device path, it would have to be a complete cutover which would likely involve me being on the receiving end of some angry emails. For PPC I've been playing with the macio device because MacOS refused to boot unless the nodes are named "ata-3" and "ata-4". So far I've only been able to do this by implementing a "dummy" macio Bus, reworking and attaching the macio-ide device to it, implementing minial Bus support, and then overriding the fw path function to rewrite the device name based upon its QOM type. That's a whole lot of work just to rename a device from "ide" to "ata-3" in the DT. If you take a look at the function Thomas mentioned in his email (https://git.qemu.org/?p=qemu.git;a=blob;f=hw/ppc/spapr.c;h=421b2dd09b515502cd11ccdd26420a8117f80cda;hb=e1ea55668ffe6ce558a063f3a9621b761738e1f2#l2866) suddenly it makes sense why I had to suggest patches for naming PCI devices: the SLOF/SPAPR authors decided to replace the entire FwPathProvider so then all that is necessary is to rewrite the paths for the relevant devices in one place; this also nicely handles the difference between IDE vs. SCSI vs. USB vs. virtio DT nodes. I certainly think it's worth keeping the PCI/sysbus patches I submitted to simplify the required logic, however it's clear to me that the above solution from SPAPR is going to be the best way forward for PPC and SPARC. Presumably this also explains why the patches didn't exist in the first place because the SLOF/SPAPR folks ignored the existing infrastructure and went ahead and did their own thing. From a design perspective I can completely understand why someone would come up with a design with a 1:1 correspondence between qdev and fw paths, but in reality it's the details that mean this just doesn't quite work in real life. In particular ISTM it's a big red flag that both IEEE-1275-based BIOSes, OpenBIOS and SLOF (upon which the design is heavily influenced) have to ignore the infrastructure based upon qdev and provide their own implementations. Are there any other similar issues around other BIOSes, e.g. s390, SeaBIOS at all? ATB, Mark. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Qemu-devel] How to generate custom fw paths for IDE devices? 2018-07-19 17:19 ` Mark Cave-Ayland @ 2018-07-19 19:03 ` Laszlo Ersek 0 siblings, 0 replies; 10+ messages in thread From: Laszlo Ersek @ 2018-07-19 19:03 UTC (permalink / raw) To: Mark Cave-Ayland, qemu-devel; +Cc: Kevin Wolf, jsnow, armbru, qemu-block On 07/19/18 19:19, Mark Cave-Ayland wrote: > On 19/07/18 09:29, Laszlo Ersek wrote: > >> (updating Marcel's address to his GMail one) >> >> On 07/18/18 23:13, Mark Cave-Ayland wrote: >>> Hi all, >>> >>> Following on from a couple of patches I've previously posted to the >>> mailing list at >>> https://lists.gnu.org/archive/html/qemu-devel/2018-06/msg08836.html >>> I've made some good progress with trying to add bootindex support to >>> OpenBIOS but I'm stuck with generating the IDE device paths from >>> QEMU. >>> >>> According to OpenBIOS the device path for a cdrom on a sun4u machine >>> should be: >>> >>> /pci@1fe,0/pci@1,1/ide@3/ide1@8100/cdrom@0 >>> >>> whereas with my working patchset I'm currently generating: >>> >>> /pci@1fe,0/pci@1,1/ide@3/drive@1 >>> >>> The issue is that the drive@1 part is being generated by the IDE >>> drive device attached to the IDE bus in hw/ide/qdev.c, and so I >>> think I need to override idebus_get_fw_dev_path() to manually >>> generate the remainder of the path including both the controller and >>> the correctly named drive node. >>> >>> One option may be to consider subclassing IDEBus and overriding >>> idebus_get_fw_dev_path() there, but the cmd646 device is a child of >>> TYPE_PCI_IDE which has its own internal IDEBus and so it seems >>> overriding it is impossible. >>> >>> Can anyone point me in the right direction as to how to generate the >>> correct fw path for IDE devices in the above format for sun4u >>> machines? >> >> What prevents you from recognizing, in the guest firmware, the >> OpenFirmware device path that is currently generated by QEMU? > > In a word: compatibility. With the older SPARC/PPC machines the OSs > are *very* picky about device names and often make assumptions about > the DT layout instead of parsing it properly, simply because at that > time no-one really thought of running the software on anything but a > real machine. > >> I mean, the device path generated by QEMU looks technically correct; >> it reflects how the IDE controller sits in a PCI B/D/F, and how the >> IDE drive sits on an IDE controller. Or do you actually have an >> intermediate IDE controller (at "address 0x8100" on the top IDE >> controller) in the sun4u machine type? Is the address 0x8100 actually >> needed by the firmware? >> >> If so, perhaps you could turn that intermediate IDE controller >> ("internal IDEBus") into its own class, and chain the instance of >> that class like the rest of the bus controllers are chained. (Just >> speculating...) > > In the case of the IDE device, the devices represent the > primary/secondary interfaces and not the separate controllers: the > primary lives at 0x8000 and the secondary at 0x8100. > > The other problem with changing this is that currently as there is no > bootindex support, these map to the legacy -hda and -cdrom options > correctly so even if I could do this, and even if all the OSs would > still parse the device path, it would have to be a complete cutover > which would likely involve me being on the receiving end of some angry > emails. > > For PPC I've been playing with the macio device because MacOS refused > to boot unless the nodes are named "ata-3" and "ata-4". So far I've > only been able to do this by implementing a "dummy" macio Bus, > reworking and attaching the macio-ide device to it, implementing > minial Bus support, and then overriding the fw path function to > rewrite the device name based upon its QOM type. That's a whole lot of > work just to rename a device from "ide" to "ata-3" in the DT. > > If you take a look at the function Thomas mentioned in his email > (https://git.qemu.org/?p=qemu.git;a=blob;f=hw/ppc/spapr.c;h=421b2dd09b515502cd11ccdd26420a8117f80cda;hb=e1ea55668ffe6ce558a063f3a9621b761738e1f2#l2866) > suddenly it makes sense why I had to suggest patches for naming PCI > devices: the SLOF/SPAPR authors decided to replace the entire > FwPathProvider so then all that is necessary is to rewrite the paths > for the relevant devices in one place; this also nicely handles the > difference between IDE vs. SCSI vs. USB vs. virtio DT nodes. > > I certainly think it's worth keeping the PCI/sysbus patches I > submitted to simplify the required logic, however it's clear to me > that the above solution from SPAPR is going to be the best way forward > for PPC and SPARC. Presumably this also explains why the patches > didn't exist in the first place because the SLOF/SPAPR folks ignored > the existing infrastructure and went ahead and did their own thing. > > From a design perspective I can completely understand why someone > would come up with a design with a 1:1 correspondence between qdev and > fw paths, but in reality it's the details that mean this just doesn't > quite work in real life. In particular ISTM it's a big red flag that > both IEEE-1275-based BIOSes, OpenBIOS and SLOF (upon which the design > is heavily influenced) have to ignore the infrastructure based upon > qdev and provide their own implementations. > > Are there any other similar issues around other BIOSes, e.g. s390, > SeaBIOS at all? I guess I could call the OVMF situation a "similar issue" :) UEFI is totally independent of OpenFirmware (device paths and anything else); it uses UEFI device paths. QEMU still populates the "bootorder" fw_cfg file with OFW devpaths, so in OVMF I had to write a parser+translator, from OFW to UEFI. It's one of the hairiest places in OVMF. Obviously the particulars of the OFW devpaths exported by QEMU (i.e., the driver-name parts) didn't matter much, as long as the OFW devpaths contained all the information necessary for the translation (including structure / nesting), and as long as they were *stable*. In practice they are stable, so that's great. Structurally / nesting-wise, they are possible to translate too. Regarding the "remaining" information content / expressive power, the OFW devpaths generated by QEMU are not expressive enough -- in general -- to *uniquely* map to UEFI boot options. So OVMF can only use them as *prefixes*, after translation. These translated prefixes are used for connecting (binding) sub-trees of bootable devices, and for filtering and reordering UEFI boot options that core edk2 code generates for those connected devices. Nowadays we rarely have to touch this code; basically only when a new kind of device (esp. bus) is added to QEMU (or needs to be enabled for this kind of boot order matching in OVMF). Oh and the PXB (PCI expander bus, a kind of extra root bridge/bus) was particular fun. For recognizing *that*, we had to modify QEMU indeed. It took a three-sided design discussion between SeaBIOS, QEMU, and OVMF. I think you remember "explicit_ofw_unit_address", and pxb_host_ofw_unit_address() :) https://git.qemu.org/?p=qemu.git;a=commitdiff;h=48ea3dedc54dbcb3c738ddef02a336739910ecfd https://github.com/tianocore/edk2/commit/5eb0b80afc4185f11379ab317f0b4d1b5520ef96 https://github.com/tianocore/edk2/commit/4fc18df9139bf5942249c77132d033a298b11c29 Laszlo ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Qemu-devel] [Qemu-block] How to generate custom fw paths for IDE devices? 2018-07-18 21:13 [Qemu-devel] How to generate custom fw paths for IDE devices? Mark Cave-Ayland 2018-07-19 8:10 ` Thomas Huth 2018-07-19 8:29 ` Laszlo Ersek @ 2018-07-25 13:03 ` Paolo Bonzini 2018-07-27 10:43 ` Mark Cave-Ayland 2 siblings, 1 reply; 10+ messages in thread From: Paolo Bonzini @ 2018-07-25 13:03 UTC (permalink / raw) To: Mark Cave-Ayland, qemu-devel Cc: Kevin Wolf, qemu-block, Laszlo Ersek, armbru, marcel On 18/07/2018 23:13, Mark Cave-Ayland wrote: > One option may be to consider subclassing IDEBus and overriding > idebus_get_fw_dev_path() there, but the cmd646 device is a child of > TYPE_PCI_IDE which has its own internal IDEBus and so it seems > overriding it is impossible. It's possible as long as you don't add any members. You can add a new const char* argument to ide_bus_new, and call it from cmd646. However, another possibility is to implement the FWPathProvider interface in the sun4u machine type. See hw/ppc/spapr.c for an example. Thanks, Paolo ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Qemu-devel] [Qemu-block] How to generate custom fw paths for IDE devices? 2018-07-25 13:03 ` [Qemu-devel] [Qemu-block] " Paolo Bonzini @ 2018-07-27 10:43 ` Mark Cave-Ayland 2018-07-27 10:47 ` Paolo Bonzini 0 siblings, 1 reply; 10+ messages in thread From: Mark Cave-Ayland @ 2018-07-27 10:43 UTC (permalink / raw) To: Paolo Bonzini, qemu-devel Cc: Kevin Wolf, marcel, Laszlo Ersek, armbru, qemu-block On 25/07/18 14:03, Paolo Bonzini wrote: > It's possible as long as you don't add any members. You can add a new > const char* argument to ide_bus_new, and call it from cmd646. > > However, another possibility is to implement the FWPathProvider > interface in the sun4u machine type. See hw/ppc/spapr.c for an example. The FWPathProvider approach seems to be working much better, however I'm still a bit stuck trying to set the bootindex for the in-built IDE interface. Normally I would use -hda for the internal IDE hd and -cdrom for the CDROM, but to support bootindex then I need to use -drive. On PPC macio has 2 IDE interfaces at 0x20000 and 0x21000 and from reading the manual I can see that the following works as expected for index between 0 and 2: $ ./qemu-system-ppc -drive id=cd,file=MacOS921-macsbug.iso,if=ide,index=0 -nographic -prom-env 'auto-boot?=false' Setting index=3 does something a little more strange compared to using plain -cdrom: $ ./qemu-system-ppc -drive id=cd,file=MacOS921-macsbug.iso,if=ide,media=cdrom,index=3 -nographic -prom-env 'auto-boot?=false' 0 > show-devs fff8990c /pci@80000000/mac-io@3/ata-3@20000 (ata) fff89c98 /pci@80000000/mac-io@3/ata-3@21000 (ata) fff8a024 /pci@80000000/mac-io@3/ata-3@21000/cdrom@0 (block) fff8a4fc /pci@80000000/mac-io@3/ata-3@21000/cdrom@0/disk@1 (block) The issue here seems to be that according to "info qtree" there is *always* an ide-cd device plugged into the location equivalent to that of -cdrom, and so with the above command QEMU ends up adding a second ide-cd device to the ide.1 bus which confuses OpenBIOS. Is this deliberate behaviour? Finally it seems I can't set bootindex with if=ide: $ ./qemu-system-ppc -drive id=cd,file=MacOS921-macsbug.iso,if=ide,index=0 -device ide-cd,drive=cd,bootindex=0 -nographic -prom-env 'auto-boot?=false' qemu-system-ppc: -device ide-cd,drive=cd,bootindex=0: Drive 'cd' is already in use because it has been automatically connected to another device (did you need 'if=none' in the drive options?) And if I try if=none as suggested then according to "info qtree" the drive never gets attached to the in-built ide.0 bus in the first place: $ ./qemu-system-ppc -drive id=cd,file=MacOS921-macsbug.iso,if=none,index=0 -device ide-cd,drive=cd,bootindex=0 -nographic -prom-env 'auto-boot?=false' I'm sure that I'm missing something really obvious here related to in-built devices but I can't quite see it at the moment... ATB, Mark. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Qemu-devel] [Qemu-block] How to generate custom fw paths for IDE devices? 2018-07-27 10:43 ` Mark Cave-Ayland @ 2018-07-27 10:47 ` Paolo Bonzini 2018-07-27 11:00 ` Mark Cave-Ayland 0 siblings, 1 reply; 10+ messages in thread From: Paolo Bonzini @ 2018-07-27 10:47 UTC (permalink / raw) To: Mark Cave-Ayland, qemu-devel Cc: Kevin Wolf, marcel, Laszlo Ersek, armbru, qemu-block On 27/07/2018 12:43, Mark Cave-Ayland wrote: > The issue here seems to be that according to "info qtree" there is > *always* an ide-cd device plugged into the location equivalent to that > of -cdrom, and so with the above command QEMU ends up adding a second > ide-cd device to the ide.1 bus which confuses OpenBIOS. Is this > deliberate behaviour? Yes, the default CD-ROM is always placed as secondary/master. If you use -device ide-cd the implicit CD-ROM should go away. However, -drive alone doesn't have that effect (probably for backwards compatibility reasons, this predates me even though by only a few months). Alternatively, you can use -nodefaults of course. Thanks, Paolo ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [Qemu-devel] [Qemu-block] How to generate custom fw paths for IDE devices? 2018-07-27 10:47 ` Paolo Bonzini @ 2018-07-27 11:00 ` Mark Cave-Ayland 0 siblings, 0 replies; 10+ messages in thread From: Mark Cave-Ayland @ 2018-07-27 11:00 UTC (permalink / raw) To: Paolo Bonzini, qemu-devel Cc: Kevin Wolf, marcel, Laszlo Ersek, armbru, qemu-block On 27/07/18 11:47, Paolo Bonzini wrote: > On 27/07/2018 12:43, Mark Cave-Ayland wrote: >> The issue here seems to be that according to "info qtree" there is >> *always* an ide-cd device plugged into the location equivalent to that >> of -cdrom, and so with the above command QEMU ends up adding a second >> ide-cd device to the ide.1 bus which confuses OpenBIOS. Is this >> deliberate behaviour? > > Yes, the default CD-ROM is always placed as secondary/master. > > If you use -device ide-cd the implicit CD-ROM should go away. However, > -drive alone doesn't have that effect (probably for backwards > compatibility reasons, this predates me even though by only a few months). I see, thanks for the detailed explanation. So in that case shouldn't the following work? $ ./qemu-system-ppc -drive id=cd,file=MacOS921-macsbug.iso,if=ide,media=cdrom -device ide-cd,drive=cd,bootindex=0 -nographic -prom-env 'auto-boot?=false' qemu-system-ppc: -device ide-cd,drive=cd,bootindex=0: Drive 'cd' is already in use because it has been automatically connected to another device (did you need 'if=none' in the drive options?) From what I can see you must have if=ide present so that the code will take into account that the machine block_default_type is set to IF_IDE and understand it's the existing internal IDE buses that need to be (re)used? > Alternatively, you can use -nodefaults of course. For the moment I'd like to come up with equivalents to the -hda and -cdrom options to allow users to switch to the new syntax, and of course this is all a pre-cursor to adding virtio support to OpenBIOS :) It seems to me that -nodefaults is intended more for tools like libvirt that want to build up a machine from scratch, although again there is always the issue as to how to handle internal devices i.e. the difference between plugging a drive into an internal IDE interface vs. adding one into a spare PCI slot via -device and instead plugging the drive into that. ATB, Mark. ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2018-07-27 11:00 UTC | newest] Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2018-07-18 21:13 [Qemu-devel] How to generate custom fw paths for IDE devices? Mark Cave-Ayland 2018-07-19 8:10 ` Thomas Huth 2018-07-19 16:46 ` Mark Cave-Ayland 2018-07-19 8:29 ` Laszlo Ersek 2018-07-19 17:19 ` Mark Cave-Ayland 2018-07-19 19:03 ` Laszlo Ersek 2018-07-25 13:03 ` [Qemu-devel] [Qemu-block] " Paolo Bonzini 2018-07-27 10:43 ` Mark Cave-Ayland 2018-07-27 10:47 ` Paolo Bonzini 2018-07-27 11:00 ` Mark Cave-Ayland
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