[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v2] xen-platform: separate unplugging of NVMe disks
> -----Original Message----- > From: Stefano Stabellini [mailto:sstabellini@xxxxxxxxxx] > Sent: 24 March 2017 00:51 > To: Paul Durrant <Paul.Durrant@xxxxxxxxxx> > Cc: qemu-devel@xxxxxxxxxx; xen-devel@xxxxxxxxxxxxxxxxxxxx; Stefano > Stabellini <sstabellini@xxxxxxxxxx>; Anthony Perard > <anthony.perard@xxxxxxxxxx> > Subject: Re: [PATCH v2] xen-platform: separate unplugging of NVMe disks > > On Thu, 23 Mar 2017, Paul Durrant wrote: > > Commit 090fa1c8 "add support for unplugging NVMe disks..." extended the > > existing disk unplug flag to cover NVMe disks as well as IDE and SCSI. > > > > The recent thread on the xen-devel mailing list [1] has highlighted that > > this is not desirable behaviour: PV frontends should be able to distinguish > > NVMe disks from other types of disk and should have separate control > over > > whether they are unplugged. > > > > This patch defines a new bit in the unplug mask for this purpose and also > > tidies up the definitions of, and improves the comments regarding, the > > previously exiting bits in the protocol. > > > > [1] https://lists.xen.org/archives/html/xen-devel/2017-03/msg02924.html > > > > Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx> > > -- > > Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx> > > Cc: Anthony Perard <anthony.perard@xxxxxxxxxx> > > > > NOTE: A companion patch will be submitted to xen-devel to align the > > unplug protocol documentation once this patch is acked. > > The companion patch needs to be acked before this patch gets applied. In > fact, I would prefer if the changeset of the Xen commit was added to > this patch description. > > If you add that, then you can repost this with > > Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx> > Ok. I'll cc you on the xen docs patch too. Paul > > > v2: > > - Fix the commit comment > > --- > > hw/i386/xen/xen_platform.c | 47 > ++++++++++++++++++++++++++++++++++------------ > > 1 file changed, 35 insertions(+), 12 deletions(-) > > > > diff --git a/hw/i386/xen/xen_platform.c b/hw/i386/xen/xen_platform.c > > index 6010f35..983d532 100644 > > --- a/hw/i386/xen/xen_platform.c > > +++ b/hw/i386/xen/xen_platform.c > > @@ -87,10 +87,30 @@ static void log_writeb(PCIXenPlatformState *s, char > val) > > } > > } > > > > -/* Xen Platform, Fixed IOPort */ > > -#define UNPLUG_ALL_DISKS 1 > > -#define UNPLUG_ALL_NICS 2 > > -#define UNPLUG_AUX_IDE_DISKS 4 > > +/* > > + * Unplug device flags. > > + * > > + * The logic got a little confused at some point in the past but this is > > + * what they do now. > > + * > > + * bit 0: Unplug all IDE and SCSI disks. > > + * bit 1: Unplug all NICs. > > + * bit 2: Unplug IDE disks except primary master. This is overridden if > > + * bit 0 is also present in the mask. > > + * bit 3: Unplug all NVMe disks. > > + * > > + */ > > +#define _UNPLUG_IDE_SCSI_DISKS 0 > > +#define UNPLUG_IDE_SCSI_DISKS (1u << _UNPLUG_IDE_SCSI_DISKS) > > + > > +#define _UNPLUG_ALL_NICS 1 > > +#define UNPLUG_ALL_NICS (1u << _UNPLUG_ALL_NICS) > > + > > +#define _UNPLUG_AUX_IDE_DISKS 2 > > +#define UNPLUG_AUX_IDE_DISKS (1u << _UNPLUG_AUX_IDE_DISKS) > > + > > +#define _UNPLUG_NVME_DISKS 3 > > +#define UNPLUG_NVME_DISKS (1u << _UNPLUG_NVME_DISKS) > > > > static void unplug_nic(PCIBus *b, PCIDevice *d, void *o) > > { > > @@ -111,7 +131,7 @@ static void unplug_disks(PCIBus *b, PCIDevice *d, > void *opaque) > > { > > uint32_t flags = *(uint32_t *)opaque; > > bool aux = (flags & UNPLUG_AUX_IDE_DISKS) && > > - !(flags & UNPLUG_ALL_DISKS); > > + !(flags & UNPLUG_IDE_SCSI_DISKS); > > > > /* We have to ignore passthrough devices */ > > if (!strcmp(d->name, "xen-pci-passthrough")) { > > @@ -124,12 +144,16 @@ static void unplug_disks(PCIBus *b, PCIDevice *d, > void *opaque) > > break; > > > > case PCI_CLASS_STORAGE_SCSI: > > - case PCI_CLASS_STORAGE_EXPRESS: > > if (!aux) { > > object_unparent(OBJECT(d)); > > } > > break; > > > > + case PCI_CLASS_STORAGE_EXPRESS: > > + if (flags & UNPLUG_NVME_DISKS) { > > + object_unparent(OBJECT(d)); > > + } > > + > > default: > > break; > > } > > @@ -147,10 +171,9 @@ static void platform_fixed_ioport_writew(void > *opaque, uint32_t addr, uint32_t v > > switch (addr) { > > case 0: { > > PCIDevice *pci_dev = PCI_DEVICE(s); > > - /* Unplug devices. Value is a bitmask of which devices to > > - unplug, with bit 0 the disk devices, bit 1 the network > > - devices, and bit 2 the non-primary-master IDE devices. */ > > - if (val & (UNPLUG_ALL_DISKS | UNPLUG_AUX_IDE_DISKS)) { > > + /* Unplug devices. See comment above flag definitions */ > > + if (val & (UNPLUG_IDE_SCSI_DISKS | UNPLUG_AUX_IDE_DISKS | > > + UNPLUG_NVME_DISKS)) { > > DPRINTF("unplug disks\n"); > > pci_unplug_disks(pci_dev->bus, val); > > } > > @@ -338,14 +361,14 @@ static void xen_platform_ioport_writeb(void > *opaque, hwaddr addr, > > * If VMDP was to control both disk and LAN it would use 4. > > * If it controlled just disk or just LAN, it would use 8 > > below. > > */ > > - pci_unplug_disks(pci_dev->bus, UNPLUG_ALL_DISKS); > > + pci_unplug_disks(pci_dev->bus, UNPLUG_IDE_SCSI_DISKS); > > pci_unplug_nics(pci_dev->bus); > > } > > break; > > case 8: > > switch (val) { > > case 1: > > - pci_unplug_disks(pci_dev->bus, UNPLUG_ALL_DISKS); > > + pci_unplug_disks(pci_dev->bus, UNPLUG_IDE_SCSI_DISKS); > > break; > > case 2: > > pci_unplug_nics(pci_dev->bus); > > -- > > 2.1.4 > > _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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