Re: [Qemu-devel] [PATCH v4 02/10] kvm: remove hard dependency on pci

[Pierre Morel]

On 21/08/2017 11:16, Cornelia Huck wrote:
> The msi routing code in kvm calls some pci functions: provide
> some stubs to enable builds without pci.
>
> Also, to make this more obvious, guard them via a pci_available boolean
> (which also can be reused in other places).
>
> Fixes: e1d4fb2de ("kvm-irqchip: x86: add msi route notify fn")
> Fixes: 767a554a0 ("kvm-all: Pass requester ID to MSI routing functions")
> Signed-off-by: Cornelia Huck <address@hidden>
> ---
>   accel/kvm/kvm-all.c  |  6 +++---
>   hw/pci/pci-stub.c    | 15 +++++++++++++++
>   hw/pci/pci.c         |  2 ++
>   include/hw/pci/pci.h |  2 ++
>   4 files changed, 22 insertions(+), 3 deletions(-)
>
> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
> index 46ce479dc3..f85553a851 100644
> --- a/accel/kvm/kvm-all.c
> +++ b/accel/kvm/kvm-all.c
> @@ -1248,7 +1248,7 @@ int kvm_irqchip_add_msi_route(KVMState *s, int vector, 
> PCIDevice *dev)
>       int virq;
>       MSIMessage msg = {0, 0};
>
> -    if (dev) {
> +    if (pci_available && dev) {
>           msg = pci_get_msi_message(dev, vector);
>       }

Hi Conny,

I did not find a case where pci_available is false and dev is true.
but anyway, sure is sure.


> @@ -1271,7 +1271,7 @@ int kvm_irqchip_add_msi_route(KVMState *s, int vector, 
> PCIDevice *dev)
>       kroute.u.msi.address_lo = (uint32_t)msg.address;
>       kroute.u.msi.address_hi = msg.address >> 32;
>       kroute.u.msi.data = le32_to_cpu(msg.data);
> -    if (kvm_msi_devid_required()) {
> +    if (pci_available && kvm_msi_devid_required()) {
>           kroute.flags = KVM_MSI_VALID_DEVID;
>           kroute.u.msi.devid = pci_requester_id(dev);
>       }
> @@ -1309,7 +1309,7 @@ int kvm_irqchip_update_msi_route(KVMState *s, int virq, 
> MSIMessage msg,
>       kroute.u.msi.address_lo = (uint32_t)msg.address;
>       kroute.u.msi.address_hi = msg.address >> 32;
>       kroute.u.msi.data = le32_to_cpu(msg.data);
> -    if (kvm_msi_devid_required()) {
> +    if (pci_available && kvm_msi_devid_required()) {
>           kroute.flags = KVM_MSI_VALID_DEVID;
>           kroute.u.msi.devid = pci_requester_id(dev);
>       }
> diff --git a/hw/pci/pci-stub.c b/hw/pci/pci-stub.c
> index ecad664946..ace43821ca 100644
> --- a/hw/pci/pci-stub.c
> +++ b/hw/pci/pci-stub.c
> @@ -23,10 +23,12 @@
>   #include "monitor/monitor.h"
>   #include "qapi/qmp/qerror.h"
>   #include "hw/pci/pci.h"
> +#include "hw/pci/msi.h"

I think you forgot that...

>   #include "qmp-commands.h"
>   #include "hw/pci/msi.h"

...you already have it included here. Didn't you ?

>   bool msi_nonbroken;
> +bool pci_available;
>
>   PciInfoList *qmp_query_pci(Error **errp)
>   {
> @@ -38,3 +40,16 @@ void hmp_pcie_aer_inject_error(Monitor *mon, const QDict 
> *qdict)
>   {
>       monitor_printf(mon, "PCI devices not supported\n");
>   }
> +
> +/* kvm-all wants this */
> +MSIMessage pci_get_msi_message(PCIDevice *dev, int vector)
> +{
> +    g_assert(false);
> +    return (MSIMessage){};
> +}
> +
> +uint16_t pci_requester_id(PCIDevice *dev)
> +{
> +    g_assert(false);
> +    return 0;
> +}
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index 258fbe51e2..26f346db2c 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -49,6 +49,8 @@
>   # define PCI_DPRINTF(format, ...)       do { } while (0)
>   #endif
>
> +bool pci_available = true;
> +
>   static void pcibus_dev_print(Monitor *mon, DeviceState *dev, int indent);
>   static char *pcibus_get_dev_path(DeviceState *dev);
>   static char *pcibus_get_fw_dev_path(DeviceState *dev);
> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
> index e598b095eb..8bb6449dd7 100644
> --- a/include/hw/pci/pci.h
> +++ b/include/hw/pci/pci.h
> @@ -10,6 +10,8 @@
>
>   #include "hw/pci/pcie.h"
>
> +extern bool pci_available;
> +
>   /* PCI bus */
>
>   #define PCI_DEVFN(slot, func)   ((((slot) & 0x1f) << 3) | ((func) & 0x07))

otherwise LGTM

Regards,

Pierre


--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany