From: Alexandru Elisei <alexandru.elisei@arm.com>
To: Andre Przywara <andre.przywara@arm.com>
Cc: kvm@vger.kernel.org, will@kernel.org,
julien.thierry.kdev@gmail.com, sami.mujawar@arm.com,
lorenzo.pieralisi@arm.com, maz@kernel.org
Subject: Re: [PATCH v2 kvmtool 15/30] virtio: Don't ignore initialization failures
Date: Fri, 6 Mar 2020 11:20:00 +0000 [thread overview]
Message-ID: <ad0199a8-bd18-4031-3489-eca9865b68fb@arm.com> (raw)
In-Reply-To: <20200130145120.0cad4a14@donnerap.cambridge.arm.com>
Hi,
On 1/30/20 2:51 PM, Andre Przywara wrote:
> On Thu, 23 Jan 2020 13:47:50 +0000
> Alexandru Elisei <alexandru.elisei@arm.com> wrote:
>
> Hi,
>
>> Don't ignore an error in the bus specific initialization function in
>> virtio_init; don't ignore the result of virtio_init; and don't return 0
>> in virtio_blk__init and virtio_scsi__init when we encounter an error.
>> Hopefully this will save some developer's time debugging faulty virtio
>> devices in a guest.
> Seems like the right thing to do, but I was wondering how you triggered this? AFAICS virtio_init only fails when calloc() fails or you pass an illegal transport, with the latter looking like being hard coded to one of the two supported.
I haven't triggered it. I found it by inspection. The transport-specific
initialization functions can fail for various reasons (ioport_register or
kvm__register_mmio can fail because some device emulation claimed all the MMIO
space or the MMIO space was configured incorrectly in the kvm-arch.h header file;
or memory allocation failed, etc) and this is the reason they return an int.
Because of this, virtio_init can fail and this is the reason it too returns an
int. It makes sense to check that the protocol that your device uses is actually
working.
>
> One minor thing below ...
[..]
>> diff --git a/virtio/net.c b/virtio/net.c
>> index 091406912a24..425c13ba1136 100644
>> --- a/virtio/net.c
>> +++ b/virtio/net.c
>> @@ -910,7 +910,7 @@ done:
>>
>> static int virtio_net__init_one(struct virtio_net_params *params)
>> {
>> - int i, err;
>> + int i, r;
>> struct net_dev *ndev;
>> struct virtio_ops *ops;
>> enum virtio_trans trans = VIRTIO_DEFAULT_TRANS(params->kvm);
>> @@ -920,10 +920,8 @@ static int virtio_net__init_one(struct virtio_net_params *params)
>> return -ENOMEM;
>>
>> ops = malloc(sizeof(*ops));
>> - if (ops == NULL) {
>> - err = -ENOMEM;
>> - goto err_free_ndev;
>> - }
>> + if (ops == NULL)
>> + return -ENOMEM;
> Doesn't that leave struct net_dev allocated? I am happy with removing the goto, but we should free(ndev) before we return, I think.
Nope, the cleanup routine in virtio_net__exit takes care of deallocating it (you
get there from virtio_net__init if virtio_net__init_one fails).
Thanks,
Alex
next prev parent reply other threads:[~2020-03-06 11:20 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-23 13:47 [PATCH v2 kvmtool 00/30] Add reassignable BARs and PCIE 1.1 support Alexandru Elisei
2020-01-23 13:47 ` [PATCH v2 kvmtool 01/30] Makefile: Use correct objcopy binary when cross-compiling for x86_64 Alexandru Elisei
2020-01-23 13:47 ` [PATCH v2 kvmtool 02/30] hw/i8042: Compile only for x86 Alexandru Elisei
2020-01-27 18:07 ` Andre Przywara
2020-01-23 13:47 ` [PATCH v2 kvmtool 03/30] pci: Fix BAR resource sizing arbitration Alexandru Elisei
2020-01-27 18:07 ` Andre Przywara
2020-01-23 13:47 ` [PATCH v2 kvmtool 04/30] Remove pci-shmem device Alexandru Elisei
2020-01-23 13:47 ` [PATCH v2 kvmtool 05/30] Check that a PCI device's memory size is power of two Alexandru Elisei
2020-01-27 18:07 ` Andre Przywara
2020-01-23 13:47 ` [PATCH v2 kvmtool 06/30] arm/pci: Advertise only PCI bus 0 in the DT Alexandru Elisei
2020-01-27 18:08 ` Andre Przywara
2020-01-23 13:47 ` [PATCH v2 kvmtool 07/30] ioport: pci: Move port allocations to PCI devices Alexandru Elisei
2020-02-07 17:02 ` Andre Przywara
2020-01-23 13:47 ` [PATCH v2 kvmtool 08/30] pci: Fix ioport allocation size Alexandru Elisei
2020-01-23 13:47 ` [PATCH v2 kvmtool 09/30] arm/pci: Fix PCI IO region Alexandru Elisei
2020-01-29 18:16 ` Andre Przywara
2020-03-04 16:20 ` Alexandru Elisei
2020-03-05 13:06 ` Alexandru Elisei
2020-01-23 13:47 ` [PATCH v2 kvmtool 10/30] virtio/pci: Make memory and IO BARs independent Alexandru Elisei
2020-01-29 18:16 ` Andre Przywara
2020-03-05 15:41 ` Alexandru Elisei
2020-01-23 13:47 ` [PATCH v2 kvmtool 11/30] vfio/pci: Allocate correct size for MSIX table and PBA BARs Alexandru Elisei
2020-01-29 18:16 ` Andre Przywara
2020-01-23 13:47 ` [PATCH v2 kvmtool 12/30] vfio/pci: Don't assume that only even numbered BARs are 64bit Alexandru Elisei
2020-01-30 14:50 ` Andre Przywara
2020-01-23 13:47 ` [PATCH v2 kvmtool 13/30] vfio/pci: Ignore expansion ROM BAR writes Alexandru Elisei
2020-01-30 14:50 ` Andre Przywara
2020-01-30 15:52 ` Alexandru Elisei
2020-01-23 13:47 ` [PATCH v2 kvmtool 14/30] vfio/pci: Don't access potentially unallocated regions Alexandru Elisei
2020-01-29 18:17 ` Andre Przywara
2020-03-06 10:54 ` Alexandru Elisei
2020-01-23 13:47 ` [PATCH v2 kvmtool 15/30] virtio: Don't ignore initialization failures Alexandru Elisei
2020-01-30 14:51 ` Andre Przywara
2020-03-06 11:20 ` Alexandru Elisei [this message]
2020-03-30 9:27 ` André Przywara
2020-01-23 13:47 ` [PATCH v2 kvmtool 16/30] Don't ignore errors registering a device, ioport or mmio emulation Alexandru Elisei
2020-01-30 14:51 ` Andre Przywara
2020-03-06 11:28 ` Alexandru Elisei
2020-01-23 13:47 ` [PATCH v2 kvmtool 17/30] hw/vesa: Don't ignore fatal errors Alexandru Elisei
2020-01-30 14:52 ` Andre Przywara
2020-03-06 12:33 ` Alexandru Elisei
2020-01-23 13:47 ` [PATCH v2 kvmtool 18/30] hw/vesa: Set the size for BAR 0 Alexandru Elisei
2020-02-03 12:20 ` Andre Przywara
2020-02-03 12:27 ` Alexandru Elisei
2020-02-05 17:00 ` Andre Przywara
2020-03-06 12:40 ` Alexandru Elisei
2020-01-23 13:47 ` [PATCH v2 kvmtool 19/30] Use independent read/write locks for ioport and mmio Alexandru Elisei
2020-02-03 12:23 ` Andre Przywara
2020-02-05 11:25 ` Alexandru Elisei
2020-01-23 13:47 ` [PATCH v2 kvmtool 20/30] pci: Add helpers for BAR values and memory/IO space access Alexandru Elisei
2020-02-05 17:00 ` Andre Przywara
2020-02-05 17:02 ` Alexandru Elisei
2020-01-23 13:47 ` [PATCH v2 kvmtool 21/30] virtio/pci: Get emulated region address from BARs Alexandru Elisei
2020-02-05 17:01 ` Andre Przywara
2020-01-23 13:47 ` [PATCH v2 kvmtool 22/30] vfio: Destroy memslot when unmapping the associated VAs Alexandru Elisei
2020-02-05 17:01 ` Andre Przywara
2020-03-09 12:38 ` Alexandru Elisei
2020-01-23 13:47 ` [PATCH v2 kvmtool 23/30] vfio: Reserve ioports when configuring the BAR Alexandru Elisei
2020-02-05 18:34 ` Andre Przywara
2020-01-23 13:47 ` [PATCH v2 kvmtool 24/30] vfio/pci: Don't write configuration value twice Alexandru Elisei
2020-02-05 18:35 ` Andre Przywara
2020-03-09 15:21 ` Alexandru Elisei
2020-01-23 13:48 ` [PATCH v2 kvmtool 25/30] pci: Implement callbacks for toggling BAR emulation Alexandru Elisei
2020-02-06 18:21 ` Andre Przywara
2020-02-07 10:12 ` Alexandru Elisei
2020-02-07 15:39 ` Alexandru Elisei
2020-01-23 13:48 ` [PATCH v2 kvmtool 26/30] pci: Toggle BAR I/O and memory space emulation Alexandru Elisei
2020-02-06 18:21 ` Andre Przywara
2020-02-07 11:08 ` Alexandru Elisei
2020-02-07 11:36 ` Andre Przywara
2020-02-07 11:44 ` Alexandru Elisei
2020-03-09 14:54 ` Alexandru Elisei
2020-01-23 13:48 ` [PATCH v2 kvmtool 27/30] pci: Implement reassignable BARs Alexandru Elisei
2020-02-07 16:50 ` Andre Przywara
2020-03-10 14:17 ` Alexandru Elisei
2020-01-23 13:48 ` [PATCH v2 kvmtool 28/30] arm/fdt: Remove 'linux,pci-probe-only' property Alexandru Elisei
2020-02-07 16:51 ` Andre Przywara
2020-02-07 17:38 ` Andre Przywara
2020-03-10 16:04 ` Alexandru Elisei
2020-01-23 13:48 ` [PATCH v2 kvmtool 29/30] vfio: Trap MMIO access to BAR addresses which aren't page aligned Alexandru Elisei
2020-02-07 16:51 ` Andre Przywara
2020-01-23 13:48 ` [PATCH v2 kvmtool 30/30] arm/arm64: Add PCI Express 1.1 support Alexandru Elisei
2020-02-07 16:51 ` Andre Przywara
2020-03-10 16:28 ` Alexandru Elisei
2020-02-07 17:02 ` [PATCH v2 kvmtool 00/30] Add reassignable BARs and PCIE " Andre Przywara
2020-05-13 14:56 ` Marc Zyngier
2020-05-13 15:15 ` Alexandru Elisei
2020-05-13 16:41 ` Alexandru Elisei
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