[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH v2 17/29] Ovmf/Xen: refactor XenBusDxe hypercall implementation



On 27 January 2015 at 12:43, Stefano Stabellini
<stefano.stabellini@xxxxxxxxxxxxx> wrote:
> On Mon, 26 Jan 2015, Ard Biesheuvel wrote:
>> This refactors the Xen hypercall implementation that is part of the
>> XenBusDxe driver, in preparation of splitting it off entirely into
>> a XenHypercallLib library. This involves:
>> - removing the dependency on XENBUS_DEVICE* pointers in the XenHypercall()
>>   prototypes
>> - moving the discovered hyperpage address to a global variable
>> - moving XenGetSharedInfoPage() to its only user XenBusDxe.c (the shared info
>>   page is not strictly part of the Xen hypercall interface, and is not used
>>   by other expected users of XenHypercallLib such as the Xen console version
>>   of SerialPortLib
>> - reimplement XenHypercall2() in C and move the indexing of the hyperpage
>>   there; the existing asm implementations are renamed to __XenHypercall2() 
>> and
>>   invoked from the new C implementation.
>>
>> Contributed-under: TianoCore Contribution Agreement 1.0
>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
>> ---
>>  OvmfPkg/XenBusDxe/EventChannel.c      | 11 +++--------
>>  OvmfPkg/XenBusDxe/GrantTable.c        |  4 ++--
>>  OvmfPkg/XenBusDxe/Ia32/hypercall.nasm |  6 +++---
>>  OvmfPkg/XenBusDxe/X64/hypercall.nasm  |  6 +++---
>>  OvmfPkg/XenBusDxe/XenBusDxe.c         | 44 
>> +++++++++++++++++++++++++++++++++++++++++++-
>>  OvmfPkg/XenBusDxe/XenBusDxe.h         |  1 -
>>  OvmfPkg/XenBusDxe/XenHypercall.c      | 50 
>> ++++++++++++++------------------------------------
>>  OvmfPkg/XenBusDxe/XenHypercall.h      | 28 +++-------------------------
>>  OvmfPkg/XenBusDxe/XenStore.c          |  4 ++--
>>  9 files changed, 73 insertions(+), 81 deletions(-)
>>
>> diff --git a/OvmfPkg/XenBusDxe/EventChannel.c 
>> b/OvmfPkg/XenBusDxe/EventChannel.c
>> index 03efaf9cb904..a86323e6adfd 100644
>> --- a/OvmfPkg/XenBusDxe/EventChannel.c
>> +++ b/OvmfPkg/XenBusDxe/EventChannel.c
>> @@ -28,7 +28,7 @@ XenEventChannelNotify (
>>    evtchn_send_t Send;
>>
>>    Send.port = Port;
>> -  ReturnCode = XenHypercallEventChannelOp (Dev, EVTCHNOP_send, &Send);
>> +  ReturnCode = XenHypercallEventChannelOp (EVTCHNOP_send, &Send);
>>    return (UINT32)ReturnCode;
>>  }
>>
>> @@ -40,15 +40,12 @@ XenBusEventChannelAllocate (
>>    OUT evtchn_port_t   *Port
>>    )
>>  {
>> -  XENBUS_PRIVATE_DATA *Private;
>>    evtchn_alloc_unbound_t Parameter;
>>    UINT32 ReturnCode;
>>
>> -  Private = XENBUS_PRIVATE_DATA_FROM_THIS (This);
>> -
>>    Parameter.dom = DOMID_SELF;
>>    Parameter.remote_dom = DomainId;
>> -  ReturnCode = (UINT32)XenHypercallEventChannelOp (Private->Dev,
>> +  ReturnCode = (UINT32)XenHypercallEventChannelOp (
>>                                     EVTCHNOP_alloc_unbound,
>>                                     &Parameter);
>>    if (ReturnCode != 0) {
>> @@ -79,10 +76,8 @@ XenBusEventChannelClose (
>>    IN evtchn_port_t   Port
>>    )
>>  {
>> -  XENBUS_PRIVATE_DATA *Private;
>>    evtchn_close_t Close;
>>
>> -  Private = XENBUS_PRIVATE_DATA_FROM_THIS (This);
>>    Close.port = Port;
>> -  return (UINT32)XenHypercallEventChannelOp (Private->Dev, EVTCHNOP_close, 
>> &Close);
>> +  return (UINT32)XenHypercallEventChannelOp (EVTCHNOP_close, &Close);
>>  }
>> diff --git a/OvmfPkg/XenBusDxe/GrantTable.c b/OvmfPkg/XenBusDxe/GrantTable.c
>> index 8405edc51bc4..53cb99f0e004 100644
>> --- a/OvmfPkg/XenBusDxe/GrantTable.c
>> +++ b/OvmfPkg/XenBusDxe/GrantTable.c
>> @@ -161,7 +161,7 @@ XenGrantTableInit (
>>      Parameters.idx = Index;
>>      Parameters.space = XENMAPSPACE_grant_table;
>>      Parameters.gpfn = (xen_pfn_t) ((UINTN) GrantTable >> EFI_PAGE_SHIFT) + 
>> Index;
>> -    ReturnCode = XenHypercallMemoryOp (Dev, XENMEM_add_to_physmap, 
>> &Parameters);
>> +    ReturnCode = XenHypercallMemoryOp (XENMEM_add_to_physmap, &Parameters);
>>      if (ReturnCode != 0) {
>>        DEBUG ((EFI_D_ERROR, "Xen GrantTable, add_to_physmap hypercall error: 
>> %d\n", ReturnCode));
>>      }
>> @@ -184,7 +184,7 @@ XenGrantTableDeinit (
>>      Parameters.domid = DOMID_SELF;
>>      Parameters.gpfn = (xen_pfn_t) ((UINTN) GrantTable >> EFI_PAGE_SHIFT) + 
>> Index;
>>      DEBUG ((EFI_D_INFO, "Xen GrantTable, removing %X\n", Parameters.gpfn));
>> -    ReturnCode = XenHypercallMemoryOp (Dev, XENMEM_remove_from_physmap, 
>> &Parameters);
>> +    ReturnCode = XenHypercallMemoryOp (XENMEM_remove_from_physmap, 
>> &Parameters);
>>      if (ReturnCode != 0) {
>>        DEBUG ((EFI_D_ERROR, "Xen GrantTable, remove_from_physmap hypercall 
>> error: %d\n", ReturnCode));
>>      }
>> diff --git a/OvmfPkg/XenBusDxe/Ia32/hypercall.nasm 
>> b/OvmfPkg/XenBusDxe/Ia32/hypercall.nasm
>> index 8547c30b81ee..e0fa71bb5ba8 100644
>> --- a/OvmfPkg/XenBusDxe/Ia32/hypercall.nasm
>> +++ b/OvmfPkg/XenBusDxe/Ia32/hypercall.nasm
>> @@ -2,13 +2,13 @@ SECTION .text
>>
>>  ; INTN
>>  ; EFIAPI
>> -; XenHypercall2 (
>> +; __XenHypercall2 (
>>  ;   IN     VOID *HypercallAddr,
>>  ;   IN OUT INTN Arg1,
>>  ;   IN OUT INTN Arg2
>>  ;   );
>> -global ASM_PFX(XenHypercall2)
>> -ASM_PFX(XenHypercall2):
>> +global ASM_PFX(__XenHypercall2)
>> +ASM_PFX(__XenHypercall2):
>>    ; Save only ebx, ecx is supposed to be a scratch register and needs to be
>>    ; saved by the caller
>>    push ebx
>> diff --git a/OvmfPkg/XenBusDxe/X64/hypercall.nasm 
>> b/OvmfPkg/XenBusDxe/X64/hypercall.nasm
>> index 177f271ef094..5e6a0c05c5c4 100644
>> --- a/OvmfPkg/XenBusDxe/X64/hypercall.nasm
>> +++ b/OvmfPkg/XenBusDxe/X64/hypercall.nasm
>> @@ -3,13 +3,13 @@ SECTION .text
>>
>>  ; INTN
>>  ; EFIAPI
>> -; XenHypercall2 (
>> +; __XenHypercall2 (
>>  ;   IN     VOID *HypercallAddr,
>>  ;   IN OUT INTN Arg1,
>>  ;   IN OUT INTN Arg2
>>  ;   );
>> -global ASM_PFX(XenHypercall2)
>> -ASM_PFX(XenHypercall2):
>> +global ASM_PFX(__XenHypercall2)
>> +ASM_PFX(__XenHypercall2):
>>    push rdi
>>    push rsi
>>    ; Copy HypercallAddr to rax
>> diff --git a/OvmfPkg/XenBusDxe/XenBusDxe.c b/OvmfPkg/XenBusDxe/XenBusDxe.c
>> index 7a7fd82d559d..d333b331b6db 100644
>> --- a/OvmfPkg/XenBusDxe/XenBusDxe.c
>> +++ b/OvmfPkg/XenBusDxe/XenBusDxe.c
>> @@ -34,6 +34,8 @@
>>  #include "XenStore.h"
>>  #include "XenBus.h"
>>
>> +#include <IndustryStandard/Xen/hvm/params.h>
>> +#include <IndustryStandard/Xen/memory.h>
>>
>>  ///
>>  /// Driver Binding Protocol instance
>> @@ -52,6 +54,46 @@ STATIC EFI_LOCK       mMyDeviceLock = 
>> EFI_INITIALIZE_LOCK_VARIABLE (TPL_CALLBACK
>>  STATIC XENBUS_DEVICE *mMyDevice = NULL;
>>
>>  /**
>> +  Map the shared_info_t page into memory.
>> +
>> +  @param Dev    A XENBUS_DEVICE instance.
>> +
>> +  @retval EFI_SUCCESS     Dev->SharedInfo whill contain a pointer to
>> +                          the shared info page
>> +  @retval EFI_LOAD_ERROR  The shared info page could not be mapped. The
>> +                          hypercall returned an error.
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +XenGetSharedInfoPage (
>> +  IN OUT XENBUS_DEVICE *Dev
>> +  )
>> +{
>> +  xen_add_to_physmap_t Parameter;
>> +
>> +  ASSERT (Dev->SharedInfo == NULL);
>> +
>> +  Parameter.domid = DOMID_SELF;
>> +  Parameter.space = XENMAPSPACE_shared_info;
>> +  Parameter.idx = 0;
>> +
>> +  //
>> +  // using reserved page because the page is not released when Linux is
>> +  // starting because of the add_to_physmap. QEMU might try to access the
>> +  // page, and fail because it have no right to do so (segv).
>> +  //
>> +  Dev->SharedInfo = AllocateReservedPages (1);
>> +  Parameter.gpfn = (UINTN) Dev->SharedInfo >> EFI_PAGE_SHIFT;
>> +  if (XenHypercallMemoryOp (XENMEM_add_to_physmap, &Parameter) != 0) {
>> +    FreePages (Dev->SharedInfo, 1);
>> +    Dev->SharedInfo = NULL;
>> +    return EFI_LOAD_ERROR;
>> +  }
>> +
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +/**
>>    Unloads an image.
>>
>>    @param  ImageHandle           Handle that identifies the image to be 
>> unloaded.
>> @@ -348,7 +390,7 @@ XenBusDxeDriverBindingStart (
>>    MmioAddr = BarDesc->AddrRangeMin;
>>    FreePool (BarDesc);
>>
>> -  Status = XenHyperpageInit (Dev);
>> +  Status = XenHyperpageInit ();
>>    if (EFI_ERROR (Status)) {
>>      DEBUG ((EFI_D_ERROR, "XenBus: Unable to retrieve the hyperpage.\n"));
>>      Status = EFI_UNSUPPORTED;
>> diff --git a/OvmfPkg/XenBusDxe/XenBusDxe.h b/OvmfPkg/XenBusDxe/XenBusDxe.h
>> index 80253b7d1ca9..9b7219906a69 100644
>> --- a/OvmfPkg/XenBusDxe/XenBusDxe.h
>> +++ b/OvmfPkg/XenBusDxe/XenBusDxe.h
>> @@ -91,7 +91,6 @@ struct _XENBUS_DEVICE {
>>    EFI_DEVICE_PATH_PROTOCOL      *DevicePath;
>>    LIST_ENTRY                    ChildList;
>>
>> -  VOID                          *Hyperpage;
>>    shared_info_t                 *SharedInfo;
>>  };
>>
>> diff --git a/OvmfPkg/XenBusDxe/XenHypercall.c 
>> b/OvmfPkg/XenBusDxe/XenHypercall.c
>> index 34d92e76b7e3..9bcf3197633e 100644
>> --- a/OvmfPkg/XenBusDxe/XenHypercall.c
>> +++ b/OvmfPkg/XenBusDxe/XenHypercall.c
>> @@ -23,9 +23,10 @@
>>  #include <IndustryStandard/Xen/hvm/params.h>
>>  #include <IndustryStandard/Xen/memory.h>
>>
>> +STATIC VOID       *Hyperpage;
>> +
>>  EFI_STATUS
>>  XenHyperpageInit (
>> -  IN OUT XENBUS_DEVICE *Dev
>>    )
>>  {
>>    EFI_HOB_GUID_TYPE   *GuidHob;
>> @@ -36,24 +37,21 @@ XenHyperpageInit (
>>      return EFI_NOT_FOUND;
>>    }
>>    XenInfo = (EFI_XEN_INFO *) GET_GUID_HOB_DATA (GuidHob);
>> -  Dev->Hyperpage = XenInfo->HyperPages;
>> +  Hyperpage = XenInfo->HyperPages;
>>    return EFI_SUCCESS;
>>  }
>>
>>  UINT64
>>  XenHypercallHvmGetParam (
>> -  IN XENBUS_DEVICE *Dev,
>>    IN UINT32        Index
>>    )
>>  {
>>    xen_hvm_param_t     Parameter;
>>    INTN                Error;
>>
>> -  ASSERT (Dev->Hyperpage != NULL);
>> -
>>    Parameter.domid = DOMID_SELF;
>>    Parameter.index = Index;
>> -  Error = XenHypercall2 ((UINT8*)Dev->Hyperpage + __HYPERVISOR_hvm_op * 32,
>> +  Error = XenHypercall2 (__HYPERVISOR_hvm_op,
>>                           HVMOP_get_param, (INTN) &Parameter);
>>    if (Error != 0) {
>>      DEBUG ((EFI_D_ERROR,
>> @@ -66,53 +64,33 @@ XenHypercallHvmGetParam (
>>
>>  INTN
>>  XenHypercallMemoryOp (
>> -  IN     XENBUS_DEVICE *Dev,
>>    IN     UINTN Operation,
>>    IN OUT VOID *Arguments
>>    )
>>  {
>> -  ASSERT (Dev->Hyperpage != NULL);
>> -  return XenHypercall2 ((UINT8*)Dev->Hyperpage + __HYPERVISOR_memory_op * 
>> 32,
>> +  return XenHypercall2 (__HYPERVISOR_memory_op,
>>                          Operation, (INTN) Arguments);
>>  }
>>
>>  INTN
>>  XenHypercallEventChannelOp (
>> -  IN     XENBUS_DEVICE *Dev,
>>    IN     INTN Operation,
>>    IN OUT VOID *Arguments
>>    )
>>  {
>> -  ASSERT (Dev->Hyperpage != NULL);
>> -  return XenHypercall2 ((UINT8*)Dev->Hyperpage + 
>> __HYPERVISOR_event_channel_op * 32,
>> +  return XenHypercall2 (__HYPERVISOR_event_channel_op,
>>                          Operation, (INTN) Arguments);
>>  }
>>
>> -EFI_STATUS
>> -XenGetSharedInfoPage (
>> -  IN OUT XENBUS_DEVICE *Dev
>> +INTN
>> +EFIAPI
>> +XenHypercall2 (
>> +  IN     INTN HypercallID,
>> +  IN OUT INTN Arg1,
>> +  IN OUT INTN Arg2
>>    )
>>  {
>> -  xen_add_to_physmap_t Parameter;
>> -
>> -  ASSERT (Dev->SharedInfo == NULL);
>> +  ASSERT (HyperPage != NULL);
>>
>> -  Parameter.domid = DOMID_SELF;
>> -  Parameter.space = XENMAPSPACE_shared_info;
>> -  Parameter.idx = 0;
>> -
>> -  //
>> -  // using reserved page because the page is not released when Linux is
>> -  // starting because of the add_to_physmap. QEMU might try to access the
>> -  // page, and fail because it have no right to do so (segv).
>> -  //
>> -  Dev->SharedInfo = AllocateReservedPages (1);
>> -  Parameter.gpfn = (UINTN) Dev->SharedInfo >> EFI_PAGE_SHIFT;
>> -  if (XenHypercallMemoryOp (Dev, XENMEM_add_to_physmap, &Parameter) != 0) {
>> -    FreePages (Dev->SharedInfo, 1);
>> -    Dev->SharedInfo = NULL;
>> -    return EFI_LOAD_ERROR;
>> -  }
>> -
>> -  return EFI_SUCCESS;
>> +  return __XenHypercall2 ((UINT8*)HyperPage + HypercallID * 32, Arg1, Arg2);
>                                         ^ shouldn't it be Hyperpage?
>

Yes, you are quite right. My build test on x86 should have spotted
this, so apparently I screwed that up in some way as well.

Cheers,
Ard.

>>  }
>> diff --git a/OvmfPkg/XenBusDxe/XenHypercall.h 
>> b/OvmfPkg/XenBusDxe/XenHypercall.h
>> index 06693830e16e..9d49e33eb5af 100644
>> --- a/OvmfPkg/XenBusDxe/XenHypercall.h
>> +++ b/OvmfPkg/XenBusDxe/XenHypercall.h
>> @@ -18,9 +18,9 @@
>>
>>  /**
>>    This function will put the two arguments in the right place (registers) 
>> and
>> -  call HypercallAddr, which correspond to an entry in the hypercall pages.
>> +  invoke the hypercall identified by HypercallID.
>>
>> -  @param HypercallAddr  A memory address where the hypercall to call is.
>> +  @param HypercallID    The symbolic ID of the hypercall to be invoked
>>    @param Arg1           First argument.
>>    @param Arg2           Second argument.
>>
>> @@ -29,7 +29,7 @@
>>  INTN
>>  EFIAPI
>>  XenHypercall2 (
>> -  IN     VOID *HypercallAddr,
>> +  IN     INTN HypercallID,
>>    IN OUT INTN Arg1,
>>    IN OUT INTN Arg2
>>    );
>> @@ -44,27 +44,23 @@ XenHypercall2 (
>>  **/
>>  EFI_STATUS
>>  XenHyperpageInit (
>> -  XENBUS_DEVICE *Dev
>>    );
>>
>>  /**
>>    Return the value of the HVM parameter Index.
>>
>> -  @param Dev    A XENBUS_DEVICE instance.
>>    @param Index  The parameter to get, e.g. HVM_PARAM_STORE_EVTCHN.
>>
>>    @return   The value of the asked parameter or 0 in case of error.
>>  **/
>>  UINT64
>>  XenHypercallHvmGetParam (
>> -  XENBUS_DEVICE *Dev,
>>    UINT32 Index
>>    );
>>
>>  /**
>>    Hypercall to do different operation on the memory.
>>
>> -  @param Dev        A XENBUS_DEVICE instance.
>>    @param Operation  The operation number, e.g. XENMEM_add_to_physmap.
>>    @param Arguments  The arguments associated to the operation.
>>
>> @@ -73,7 +69,6 @@ XenHypercallHvmGetParam (
>>  **/
>>  INTN
>>  XenHypercallMemoryOp (
>> -  IN     XENBUS_DEVICE *Dev,
>>    IN     UINTN Operation,
>>    IN OUT VOID *Arguments
>>    );
>> @@ -81,7 +76,6 @@ XenHypercallMemoryOp (
>>  /**
>>    Do an operation on the event channels.
>>
>> -  @param Dev        A XENBUS_DEVICE instance.
>>    @param Operation  The operation number, e.g. EVTCHNOP_send.
>>    @param Arguments  The argument associated to the operation.
>>
>> @@ -90,24 +84,8 @@ XenHypercallMemoryOp (
>>  **/
>>  INTN
>>  XenHypercallEventChannelOp (
>> -  IN     XENBUS_DEVICE *Dev,
>>    IN     INTN Operation,
>>    IN OUT VOID *Arguments
>>    );
>>
>> -/**
>> -  Map the shared_info_t page into memory.
>> -
>> -  @param Dev    A XENBUS_DEVICE instance.
>> -
>> -  @retval EFI_SUCCESS     Dev->SharedInfo whill contain a pointer to
>> -                          the shared info page
>> -  @retval EFI_LOAD_ERROR  The shared info page could not be mapped. The
>> -                          hypercall returned an error.
>> -**/
>> -EFI_STATUS
>> -XenGetSharedInfoPage (
>> -  IN OUT XENBUS_DEVICE *Dev
>> -  );
>> -
>>  #endif
>> diff --git a/OvmfPkg/XenBusDxe/XenStore.c b/OvmfPkg/XenBusDxe/XenStore.c
>> index 2df8f5348585..7ec1e634bc5c 100644
>> --- a/OvmfPkg/XenBusDxe/XenStore.c
>> +++ b/OvmfPkg/XenBusDxe/XenStore.c
>> @@ -1057,8 +1057,8 @@ XenStoreInit (
>>
>>    xs.Dev = Dev;
>>
>> -  xs.EventChannel = (evtchn_port_t)XenHypercallHvmGetParam (Dev, 
>> HVM_PARAM_STORE_EVTCHN);
>> -  XenStoreGpfn = (UINTN)XenHypercallHvmGetParam (Dev, HVM_PARAM_STORE_PFN);
>> +  xs.EventChannel = (evtchn_port_t)XenHypercallHvmGetParam 
>> (HVM_PARAM_STORE_EVTCHN);
>> +  XenStoreGpfn = (UINTN)XenHypercallHvmGetParam (HVM_PARAM_STORE_PFN);
>>    xs.XenStore = (VOID *) (XenStoreGpfn << EFI_PAGE_SHIFT);
>>    DEBUG ((EFI_D_INFO, "XenBusInit: XenBus rings @%p, event channel %x\n",
>>            xs.XenStore, xs.EventChannel));
>> --
>> 1.8.3.2
>>

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.