Re: [edk2-devel] [edk2-libc Patch 1/1] edk2-libc:add rdmsr_ex & wrmsr_ex functions to read/write cpu specific msrs

["Jayaprakash, N" <n.jayaprakash@intel.com>]

Hi Mike,

I have sent an updated patch v2 for review which uses the MP Services protocol API StarupThisAP() to read / write MSRs specific to CPU cores.
Please review and do the needful.

Regards,
JP

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Jayaprakash, N
Sent: Thursday, April 18, 2024 11:49 AM
To: Kinney, Michael D <michael.d.kinney@intel.com>; devel@edk2.groups.io
Cc: Rebecca Cran <rebecca@bsdio.com>
Subject: Re: [edk2-devel] [edk2-libc Patch 1/1] edk2-libc:add rdmsr_ex & wrmsr_ex functions to read/write cpu specific msrs

Thanks Mike. I shall make necessary changes and submit the PR again for review.

Regards,
JP

-----Original Message-----
From: Kinney, Michael D <michael.d.kinney@intel.com>
Sent: Thursday, April 18, 2024 10:46 AM
To: Jayaprakash, N <n.jayaprakash@intel.com>; devel@edk2.groups.io
Cc: Rebecca Cran <rebecca@bsdio.com>; Kinney, Michael D <michael.d.kinney@intel.com>
Subject: RE: [edk2-devel] [edk2-libc Patch 1/1] edk2-libc:add rdmsr_ex & wrmsr_ex functions to read/write cpu specific msrs

Please use MP Services Protocol APIs StartupAllAPs() or StarupThisAP() to read/write MSRs on other logical processors.

There and many examples of this in the UefiCpuPkg to programming MSRs on all the logical processors.

Mike

> -----Original Message-----
> From: Jayaprakash, N <n.jayaprakash@intel.com>
> Sent: Wednesday, April 17, 2024 8:16 PM
> To: Kinney, Michael D <michael.d.kinney@intel.com>; 
> devel@edk2.groups.io
> Cc: Rebecca Cran <rebecca@bsdio.com>
> Subject: RE: [edk2-devel] [edk2-libc Patch 1/1] edk2-libc:add rdmsr_ex 
> & wrmsr_ex functions to read/write cpu specific msrs
> 
> In the validation and debug scenarios, engineers tend to read MSRs and 
> write to MSRs of different CPUs.
> So we are providing a simple mechanism through these APIs to enable 
> them to do these operations.
> 
> These APIs will be part of the edk2 module of the Python interpreter 
> and will be used during the validation and debug scenarios only.
> 
> This is not for switching the BSP for OS boot. This is only used 
> during the validation and debug use cases.
> 
> Regards,
> JP
> -----Original Message-----
> From: Kinney, Michael D <michael.d.kinney@intel.com>
> Sent: Thursday, April 18, 2024 12:08 AM
> To: Jayaprakash, N <n.jayaprakash@intel.com>; devel@edk2.groups.io
> Cc: Rebecca Cran <rebecca@bsdio.com>; Kinney, Michael D 
> <michael.d.kinney@intel.com>
> Subject: RE: [edk2-devel] [edk2-libc Patch 1/1] edk2-libc:add rdmsr_ex 
> & wrmsr_ex functions to read/write cpu specific msrs
> 
> Hi JP,
> 
> Is there a reason switch BSP is being used.  That is not a common 
> operation and is typically used if the current BSP is not stable or 
> there is a good reason to switch the BSP for OS boot.
> 
> The MP Services can be used to execute a C function on APs to execute 
> MSR related instructions.
> 
> Mike
> 
> > -----Original Message-----
> > From: Jayaprakash, N <n.jayaprakash@intel.com>
> > Sent: Sunday, April 14, 2024 10:33 PM
> > To: devel@edk2.groups.io; Jayaprakash, N <n.jayaprakash@intel.com>
> > Cc: Rebecca Cran <rebecca@bsdio.com>; Kinney, Michael D 
> > <michael.d.kinney@intel.com>
> > Subject: RE: [edk2-devel] [edk2-libc Patch 1/1] edk2-libc:add
> rdmsr_ex
> > & wrmsr_ex functions to read/write cpu specific msrs
> >
> > + Rebecca and Mike,
> >
> > Would you be able to review this PR?
> >
> > Regards,
> > JP
> >
> > -----Original Message-----
> > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of 
> > Jayaprakash, N
> > Sent: Wednesday, April 10, 2024 11:49 AM
> > To: devel@edk2.groups.io
> > Cc: Jayaprakash, N <n.jayaprakash@intel.com>; Rebecca Cran 
> > <rebecca@bsdio.com>; Kinney, Michael D <michael.d.kinney@intel.com>
> > Subject: [edk2-devel] [edk2-libc Patch 1/1] edk2-libc:add rdmsr_ex & 
> > wrmsr_ex functions to read/write cpu specific msrs
> >
> > REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4746
> >
> > The rdmsr_ex and wrmsr_ex are extension APIs to the rdmsr and wrmsr 
> > APIs supported in edk2 module. These extension APIs makes it
> possible
> > to read / write MSRs from specific processors and fills an existing 
> > gap in this area.
> >
> > Cc: Rebecca Cran <rebecca@bsdio.com>
> > Cc: Michael D Kinney <michael.d.kinney@intel.com>
> > Cc: Jayaprakash N <n.jayaprakash@intel.com>
> > Signed-off-by: Jayaprakash N <n.jayaprakash@intel.com>
> > ---
> >  .../PyMod-3.6.8/Modules/edk2module.c          | 159
> > +++++++++++++++++-
> >  .../Python/Python-3.6.8/Python368.inf         |   3 +
> >  2 files changed, 158 insertions(+), 4 deletions(-)
> >
> > diff --git a/AppPkg/Applications/Python/Python-3.6.8/PyMod-
> > 3.6.8/Modules/edk2module.c b/AppPkg/Applications/Python/Python-
> > 3.6.8/PyMod-3.6.8/Modules/edk2module.c
> > index d6af8da..f1b13a6 100644
> > --- a/AppPkg/Applications/Python/Python-3.6.8/PyMod-
> > 3.6.8/Modules/edk2module.c
> > +++ b/AppPkg/Applications/Python/Python-3.6.8/PyMod-
> > 3.6.8/Modules/edk2mo
> > +++ dule.c
> > @@ -3,7 +3,7 @@
> >      Derived from posixmodule.c in Python 2.7.2.
> >
> >      Copyright (c) 2015, Daryl McDaniel. All rights reserved.<BR>
> > -    Copyright (c) 2011 - 2023, Intel Corporation. All rights
> > reserved.<BR>
> > +    Copyright (c) 2011 - 2024, Intel Corporation. All rights 
> > + reserved.<BR>
> >      This program and the accompanying materials are licensed and
> made
> > available under
> >      the terms and conditions of the BSD License that accompanies
> this
> > distribution.
> >      The full text of the license may be found at @@ -22,16 +22,23
> @@
> > #include  <wchar.h>  #include  <sys/syslimits.h>  #include  <Uefi.h>
> > +#include  <Pi/PiDxeCis.h>      // Needed for the definition of
> > EFI_AP_PROCEDURE
> >  #include  <Library/UefiLib.h>
> >  #include  <Library/PciLib.h>
> >  #include  <Library/IoLib.h>
> >  #include  <Library/UefiRuntimeServicesTableLib.h>
> > +#include  <Library/UefiBootServicesTableLib.h>
> > +#include  <Protocol/MpService.h>
> >
> >  #ifdef __cplusplus
> >  extern "C" {
> >  #endif
> >
> >  PyTypeObject EfiGuidType;
> > +EFI_MP_SERVICES_PROTOCOL   *gpMpService = NULL;
> > +UINTN                       gBSPProcessorNumber = 0;
> > +UINTN                       gNumberOfProcessors = 0;
> > +UINTN                       gNumberOfEnabledProcessors = 0;
> >
> >  extern void _swsmi( unsigned int smi_code_data, unsigned int 
> > rax_value, unsigned int rbx_value, unsigned int rcx_value, unsigned 
> > int rdx_value, unsigned int rsi_value, unsigned int rdi_value );  //
> -
> > - Support routines @@ -169,6 +176,35 @@ PyDoc_STRVAR(edk2__doc__,
> >  /* dummy version. _PyVerify_fd() is already defined in fileobject.h 
> > */  #define _PyVerify_fd_dup2(A, B) (1)
> >
> > +static EFI_STATUS
> > +MpServicesWhoAmI (
> > +  IN EFI_MP_SERVICES_PROTOCOL  *pMpService,
> > +  OUT UINTN                    *pProcessorNumber
> > +  )
> > +{
> > +  return pMpService->WhoAmI (pMpService, pProcessorNumber); }
> > +
> > +static EFI_STATUS
> > +MpServicesGetNumberOfProcessors (
> > +  IN EFI_MP_SERVICES_PROTOCOL  *pMpService,
> > +  OUT UINTN                    *pNumberOfProcessors,
> > +  OUT UINTN                    *pNumberOfEnabledProcessors
> > +
> > +  )
> > +{
> > +  return pMpService->GetNumberOfProcessors (pMpService, 
> > +pNumberOfProcessors, pNumberOfEnabledProcessors); }
> > +
> > +static EFI_STATUS
> > +MpServicesSwitchBSP (
> > +  IN EFI_MP_SERVICES_PROTOCOL  *pMpService,
> > +  IN UINTN                      ProcessorNumber
> > +  )
> > +{
> > +  return pMpService->SwitchBSP(pMpService,  ProcessorNumber, TRUE);
> }
> > +
> >  #ifndef UEFI_C_SOURCE
> >  /* Return a dictionary corresponding to the POSIX environment table 
> > */  extern char **environ; @@ -3865,6 +3901,56 @@
> edk2_rdmsr(PyObject
> > *self, PyObject *args)
> >    return Py_BuildValue("(II)", (unsigned long)veax, (unsigned 
> > long)vedx);  }
> >
> > +PyDoc_STRVAR(efi_rdmsr_ex__doc__,
> > +"rdmsr_ex(cpu, msr) -> (lower_32bits, higher_32bits)\n\ \n\ Read
> the
> > +given msr by switching to cpu and return the data as tuple.\n\ \n\ 
> > +Parameters:\n\
> > +    cpu - The cpu number in hex or int format\n\
> > +    msr - The msr in hex or int format\n\ \n\ Return Value:\n\
> > +    a tuple with lower and higher 32 bit values read from the
> msr\n\
> > +");
> > +
> > +static PyObject *
> > +edk2_rdmsr_ex(PyObject *self, PyObject *args) {
> > +  unsigned int cpu, vecx, veax, vedx;
> > +  unsigned int bsp_switched = 0;
> > +  EFI_STATUS status = 0;
> > +  UINT64   data = 0;
> > +
> > +  if (!PyArg_ParseTuple(args, "II", &cpu, &vecx))
> > +    return NULL;
> > +
> > +  Py_BEGIN_ALLOW_THREADS
> > +  if (cpu != gBSPProcessorNumber && cpu < gNumberOfProcessors)  {
> > +    //switch the BSP to the cpu
> > +    status = MpServicesSwitchBSP(gpMpService, cpu);
> > +    if (!EFI_ERROR(status))
> > +    {
> > +        bsp_switched = 1;
> > +    }
> > +  }
> > +
> > +  data = AsmReadMsr64(vecx);
> > +
> > +  if (bsp_switched)
> > +  {
> > +    // switch BSP to the saved BSP processor
> > +    MpServicesSwitchBSP(gpMpService, gBSPProcessorNumber);
> > +    // update the saved BSP processor
> > +    MpServicesWhoAmI(gpMpService, &gBSPProcessorNumber);
> > +  }
> > +  Py_END_ALLOW_THREADS
> > +  veax = (UINT32)data;
> > +  vedx = (UINT64)data >> 32;
> > +  return Py_BuildValue("(II)", (unsigned long)veax, (unsigned 
> > +long)vedx); }
> > +
> >  PyDoc_STRVAR(efi_wrmsr__doc__,
> >  "wrmsr(msr, lower_32bits, higher_32bits) -> None\n\  \n\ @@ -3889,6
> > +3975,58 @@ edk2_wrmsr(PyObject *self, PyObject *args)
> >    data = vedx << 32 | veax;
> >    Py_BEGIN_ALLOW_THREADS
> >    AsmWriteMsr64(vecx, data);
> > +  Py_END_ALLOW_THREADS
> > +  Py_INCREF(Py_None);
> > +  return Py_None;
> > +}
> > +
> > +PyDoc_STRVAR(efi_wrmsr_ex__doc__,
> > +"wrmsr_ex(cpu, msr, lower_32bits, higher_32bits) -> None\n\ \n\
> > Writes
> > +higher_32bits:lower_32bits to the given msr.\n\ \n\ Parameters:\n\
> > +    cpu - The cpu number in hex or int format\n\
> > +    msr - The msr in hex or int format\n\
> > +    lower_32bits - The lower 32 bit data for the msr\n\
> > +    higher_32bits - The higher 32 bit data for the msr\n\ \n\
> Return
> > +Value:\n\
> > +    None\n\
> > +");
> > +
> > +static PyObject *
> > +edk2_wrmsr_ex(PyObject *self, PyObject *args) {
> > +  unsigned int cpu, msr, veax, vedx;
> > +  unsigned int bsp_switched = 0;
> > +  EFI_STATUS status = 0;
> > +  UINT64   data = 0;
> > +
> > +  if (!PyArg_ParseTuple(args, "IIII", &cpu, &msr, &veax, &vedx))
> > +    return NULL;
> > +  data = (((UINT64)vedx) << 32) | veax;
> > +
> > +  Py_BEGIN_ALLOW_THREADS
> > +  if (cpu != gBSPProcessorNumber && cpu < gNumberOfProcessors)  {
> > +    //switch the BSP to the cpu
> > +    status = MpServicesSwitchBSP(gpMpService, cpu);
> > +    if (!EFI_ERROR(status))
> > +    {
> > +        bsp_switched = 1;
> > +    }
> > +  }
> > +  // write to MSR
> > +  AsmWriteMsr64(msr, data);
> > +
> > +  if (bsp_switched)
> > +  {
> > +    // switch BSP to the saved BSP processor
> > +    MpServicesSwitchBSP(gpMpService, gBSPProcessorNumber);
> > +    // update the saved BSP processor
> > +    MpServicesWhoAmI(gpMpService, &gBSPProcessorNumber);  }
> >    Py_END_ALLOW_THREADS
> >    Py_INCREF(Py_None);
> >    return Py_None;
> > @@ -4576,7 +4714,9 @@ static PyMethodDef edk2_methods[] = {  #endif
> >      {"abort",               edk2_abort,      METH_NOARGS,
> > edk2_abort__doc__},
> >      {"rdmsr",               edk2_rdmsr,
> METH_VARARGS,
> > efi_rdmsr__doc__},
> > +    {"rdmsr_ex",            edk2_rdmsr_ex,
> METH_VARARGS,
> > efi_rdmsr_ex__doc__},
> >      {"wrmsr",               edk2_wrmsr,
> METH_VARARGS,
> > efi_wrmsr__doc__},
> > +    {"wrmsr_ex",            edk2_wrmsr_ex,
> METH_VARARGS,
> > efi_wrmsr_ex__doc__},
> >      {"readpci",             edk2_readpci,
> METH_VARARGS,
> > efi_readpci__doc__},
> >      {"writepci",            edk2_writepci,
> METH_VARARGS,
> > efi_writepci__doc__},
> >      {"readmem",             posix_readmem,
> > METH_VARARGS, efi_readmem__doc__},
> > @@ -4813,13 +4953,24 @@ static struct PyModuleDef edk2module = { 
> > PyMODINIT_FUNC
> >  PyEdk2__Init(void)
> >  {
> > -    PyObject *m;
> > +    PyObject    *m;
> > +    EFI_STATUS   Status = 0;
> >
> >  #ifndef UEFI_C_SOURCE
> >    PyObject *v;
> >  #endif
> > +    Status = gBS->LocateProtocol(&gEfiMpServiceProtocolGuid, NULL,
> > &gpMpService);
> > +    if (EFI_ERROR(Status))
> > +    {
> > +        printf("Unable to locate the Protocol MpServices protocol:
> > %r\n", Status);
> > +        return NULL;
> > +    }
> > +    // Get the current BSP processor number
> > +    MpServicesWhoAmI(gpMpService, &gBSPProcessorNumber);
> > +    // Get the number of processors
> > +    MpServicesGetNumberOfProcessors(gpMpService,
> > &gNumberOfProcessors,
> > + &gNumberOfEnabledProcessors);
> >
> > -	m = PyModule_Create(&edk2module);
> > +    m = PyModule_Create(&edk2module);
> >      if (m == NULL)
> >          return m;
> >
> > @@ -4870,7 +5021,7 @@ PyEdk2__Init(void)
> >      //PyModule_AddObject(m, "statvfs_result",
> >      //                   (PyObject*) &StatVFSResultType);
> >      initialized = 1;
> > -	return m;
> > +    return m;
> >
> >  }
> >
> > diff --git a/AppPkg/Applications/Python/Python-3.6.8/Python368.inf
> > b/AppPkg/Applications/Python/Python-3.6.8/Python368.inf
> > index 8b7f677..eca98b5 100644
> > --- a/AppPkg/Applications/Python/Python-3.6.8/Python368.inf
> > +++ b/AppPkg/Applications/Python/Python-3.6.8/Python368.inf
> > @@ -46,6 +46,9 @@
> >    #BsdSocketLib
> >    #EfiSocketLib
> >
> > +[Protocols]
> > +  gEfiMpServiceProtocolGuid           ## CONSUMES
> > +
> >  [FixedPcd]
> >    gEfiMdePkgTokenSpaceGuid.PcdDebugPropertyMask|0x0F
> >    gEfiMdePkgTokenSpaceGuid.PcdDebugPrintErrorLevel|0x80000040
> > --
> > 2.40.0.windows.1
> >
> >
> >
> > 
> >








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