Re: [PATCH 2/2] libxc: enabling emulated MSI injection

[Wei Liu <liuw@liuw.name>]

On Thu, May 26, 2011 at 8:34 PM, Konrad Rzeszutek Wilk
<konrad.wilk@oracle.com> wrote:
> On Thu, May 26, 2011 at 11:09:43AM +0800, Wei Liu wrote:
>> commit 67038b5b18096b3bdcda7fe393d1be6a91dc75a6
>> Author: Wei Liu <liuw@liuw.name>
>> Date:   Thu May 26 10:27:41 2011 +0800
>>
>>     libxc: add new operation in HVMOP to deliver emulated MSI.
>
> What is the purpose of this call?

Sorry I missed this one.

Currently QEMU cannot inject MSI for emulated devices, which limits
virtio to use irq to deliver interrupts. This call is used to inject
MSI from QEMU to HVM, suggested by Stefano.

>>
>>     Signed-off-by: Wei Liu <liuw@liuw.name>
>>
>> diff --git a/tools/libxc/xc_misc.c b/tools/libxc/xc_misc.c
>> index b87bbc0..38af397 100644
>> --- a/tools/libxc/xc_misc.c
>> +++ b/tools/libxc/xc_misc.c
>> @@ -417,6 +417,35 @@ int xc_hvm_set_pci_link_route(
>>      return rc;
>>  }
>>
>> +int xc_hvm_inj_msi(
>> +    xc_interface *xch, domid_t dom, uint64_t addr, uint32_t data)
>> +{
>> +    DECLARE_HYPERCALL;
>> +    DECLARE_HYPERCALL_BUFFER(struct xen_hvm_inj_msi, arg);
>> +    int rc;
>> +
>> +    arg = xc_hypercall_buffer_alloc(xch, arg, sizeof(*arg));
>> +    if ( arg == NULL )
>> +    {
>> +        PERROR("Could not allocate memory for xc_hvm_inj_msi hypercall");
>> +        return -1;
>> +    }
>> +
>> +    hypercall.op     = __HYPERVISOR_hvm_op;
>> +    hypercall.arg[0] = HVMOP_inj_msi;
>> +    hypercall.arg[1] = HYPERCALL_BUFFER_AS_ARG(arg);
>> +
>> +    arg->domid = dom;
>> +    arg->addr  = addr;
>> +    arg->data  = data;
>
> Shouldn't those be done before you make the HYPERCALL_BUFFER_AS_ARG
> in case they get bounced?
>
>> +
>> +    rc = do_xen_hypercall(xch, &hypercall);
>> +
>> +    xc_hypercall_buffer_free(xch, arg);
>> +
>> +    return rc;
>> +}
>> +
>>  int xc_hvm_track_dirty_vram(
>>      xc_interface *xch, domid_t dom,
>>      uint64_t first_pfn, uint64_t nr,
>> diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
>> index 9a4355f..2442c84 100644
>> --- a/tools/libxc/xenctrl.h
>> +++ b/tools/libxc/xenctrl.h
>> @@ -1387,6 +1387,8 @@ int xc_hvm_set_isa_irq_level(
>>  int xc_hvm_set_pci_link_route(
>>      xc_interface *xch, domid_t dom, uint8_t link, uint8_t isa_irq);
>>
>> +int xc_hvm_inj_msi(
>> +    xc_interface *xch, domid_t dom, uint64_t addr, uint32_t data);
>>
>>  /*
>>   * Track dirty bit changes in the VRAM area
>>
>> --
>> Best regards
>> Wei Liu
>> Twitter: @iliuw
>> Site: http://liuw.name
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xensource.com
>> http://lists.xensource.com/xen-devel
>



-- 
Best regards
Wei Liu
Twitter: @iliuw
Site: http://liuw.name