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From: Roy Hopkins <roy.hopkins@suse.com>
To: "Philippe Mathieu-Daudé" <philmd@linaro.org>, qemu-devel@nongnu.org
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
	"Daniel P . Berrangé" <berrange@redhat.com>,
	"Stefano Garzarella" <sgarzare@redhat.com>,
	"Marcelo Tosatti" <mtosatti@redhat.com>,
	"Michael S . Tsirkin" <mst@redhat.com>,
	"Cornelia Huck" <cohuck@redhat.com>,
	"Marcel Apfelbaum" <marcel.apfelbaum@gmail.com>,
	"Sergio Lopez" <slp@redhat.com>,
	"Eduardo Habkost" <eduardo@habkost.net>,
	"Alistair Francis" <alistair@alistair23.me>,
	"Peter Xu" <peterx@redhat.com>,
	"David Hildenbrand" <david@redhat.com>,
	"Igor Mammedov" <imammedo@redhat.com>,
	"Tom Lendacky" <thomas.lendacky@amd.com>,
	"Michael Roth" <michael.roth@amd.com>,
	"Ani Sinha" <anisinha@redhat.com>,
	"Jörg Roedel" <jroedel@suse.com>
Subject: Re: [PATCH v2 04/10] backends/igvm: Implement parsing and processing of IGVM files
Date: Tue, 07 May 2024 15:19:47 +0100	[thread overview]
Message-ID: <ff5f80e3e5f485162020dff809a8117bf691a331.camel@suse.com> (raw)
In-Reply-To: <905678ae-09cd-4e37-8dc1-5b5e5314d0ea@linaro.org>

On Thu, 2024-04-04 at 09:58 +0200, Philippe Mathieu-Daudé wrote:
> Hi Roy,
> 
> On 3/4/24 13:11, Roy Hopkins wrote:
> > This commit adds an implementation of an IGVM loader which parses the
> > file specified as a pararameter to ConfidentialGuestSupport and provides
> > a function that uses the interface in the same object to configure and
> > populate guest memory based on the contents of the file.
> > 
> > The IGVM file is parsed when a filename is provided but the code to
> > process the IGVM file is not yet hooked into target systems. This will
> > follow in a later commit.
> > 
> > Signed-off-by: Roy Hopkins <roy.hopkins@suse.com>
> > ---
> >   backends/confidential-guest-support.c     |   4 +
> >   backends/igvm.c                           | 745 ++++++++++++++++++++++
> >   backends/meson.build                      |   1 +
> >   include/exec/confidential-guest-support.h |   5 +
> >   include/exec/igvm.h                       |  36 ++
> >   5 files changed, 791 insertions(+)
> >   create mode 100644 backends/igvm.c
> >   create mode 100644 include/exec/igvm.h
> 
> Consider enabling scripts/git.orderfile.
Ok, will do.

> 
> > diff --git a/backends/confidential-guest-support.c b/backends/confidential-
> > guest-support.c
> > index cb0bc543c0..adfe447334 100644
> > --- a/backends/confidential-guest-support.c
> > +++ b/backends/confidential-guest-support.c
> > @@ -16,6 +16,7 @@
> >   #include "exec/confidential-guest-support.h"
> >   #include "qemu/error-report.h"
> >   #include "qapi/error.h"
> > +#include "exec/igvm.h"
> >   
> >   OBJECT_DEFINE_ABSTRACT_TYPE(ConfidentialGuestSupport,
> >                               confidential_guest_support,
> > @@ -34,6 +35,9 @@ static void set_igvm(Object *obj, const char *value, Error
> > **errp)
> >       ConfidentialGuestSupport *cgs = CONFIDENTIAL_GUEST_SUPPORT(obj);
> >       g_free(cgs->igvm_filename);
> >       cgs->igvm_filename = g_strdup(value);
> > +#if defined(CONFIG_IGVM)
> 
> You don't need the #ifdef'ry because if CONFIG_IGVM you defined
> an inlined function which returns 0.
> 
> > +    igvm_file_init(cgs, errp);
> 
> You are deliberately ignoring the return value. Should the prototype
> return void? Or at least a boolean, since the return value is (-1, 0).
> 
> > +#endif
> >   }
> >   #endif
> >   
> > diff --git a/backends/igvm.c b/backends/igvm.c
> > new file mode 100644
> > index 0000000000..87e6032a2e
> > --- /dev/null
> > +++ b/backends/igvm.c
> > @@ -0,0 +1,745 @@
> > +/*
> > + * QEMU IGVM configuration backend for Confidential Guests
> > + *
> > + * Copyright (C) 2023-2024 SUSE
> > + *
> > + * Authors:
> > + *  Roy Hopkins <roy.hopkins@suse.com>
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2 or
> > later.
> > + * See the COPYING file in the top-level directory.
> > + */
> > +
> > +#include "qemu/osdep.h"
> > +
> > +#if defined(CONFIG_IGVM)
> 
> This file is only compiled when CONFIG_IGVM is set, so no need for
> this guard.
> 
> > +#include "exec/confidential-guest-support.h"
> > +#include "qemu/queue.h"
> > +#include "qemu/typedefs.h"
> 
> No need to include "qemu/typedefs.h", we get it via "qemu/osdep.h".
> 
> > +#include "exec/igvm.h"
> > +#include "qemu/error-report.h"
> > +#include "hw/boards.h"
> 
> What is used from "hw/board.h"?
> 
> > +#include "qapi/error.h"
> > +#include "exec/address-spaces.h"
> > +
> > +#include <igvm/igvm.h>
> > +#include <igvm/igvm_defs.h>
> > +#include <linux/kvm.h>
> > +
> > +typedef struct IgvmParameterData {
> > +    QTAILQ_ENTRY(IgvmParameterData) next;
> > +    uint8_t *data;
> > +    uint32_t size;
> > +    uint32_t index;
> > +} IgvmParameterData;
> > +
> > +static QTAILQ_HEAD(, IgvmParameterData) parameter_data;
> Can we store this in ConfidentialGuestSupport instead?
> 
> Possibly forward-declaring a structure, using an opaque
> pointer in ConfidentialGuestSupport ...:
> 
> typedef struct QemuIvgm QemuIvgm;
> 
> struct ConfidentialGuestSupport {
>      ...
>      QemuIvgm *ivgm;
>      ...
> };
> 
> ... and defining the struct here in igvm.c:
> 
> struct QemuIvgm {
>      char *filename;
>      IgvmHandle handle;
>      QTAILQ_HEAD(, IgvmParameterData) parameter_data;
> };
> 

That make senses. In fact, I've added QemuIgvm to hold the context of the file
as it is being processed but this is only scoped to igvm_process_file() so I
will keep it as a local variable in that function instead of adding it to
ConfidentialGuestSupport.


> > +static int directive_page_data(ConfidentialGuestSupport *cgs, int i,
> > +                               uint32_t compatibility_mask,
> > +                               const uint8_t *header_data, Error **errp);
> > +static int directive_vp_context(ConfidentialGuestSupport *cgs, int i,
> > +                                uint32_t compatibility_mask,
> > +                                const uint8_t *header_data, Error **errp);
> > +static int directive_parameter_area(ConfidentialGuestSupport *cgs, int i,
> > +                                    uint32_t compatibility_mask,
> > +                                    const uint8_t *header_data, Error
> > **errp);
> > +static int directive_parameter_insert(ConfidentialGuestSupport *cgs, int i,
> > +                                      uint32_t compatibility_mask,
> > +                                      const uint8_t *header_data, Error
> > **errp);
> > +static int directive_memory_map(ConfidentialGuestSupport *cgs, int i,
> > +                                uint32_t compatibility_mask,
> > +                                const uint8_t *header_data, Error **errp);
> > +static int directive_vp_count(ConfidentialGuestSupport *cgs, int i,
> > +                              uint32_t compatibility_mask,
> > +                              const uint8_t *header_data, Error **errp);
> > +static int directive_environment_info(ConfidentialGuestSupport *cgs, int i,
> > +                                      uint32_t compatibility_mask,
> > +                                      const uint8_t *header_data, Error
> > **errp);
> > +static int directive_required_memory(ConfidentialGuestSupport *cgs, int i,
> > +                                     uint32_t compatibility_mask,
> > +                                     const uint8_t *header_data, Error
> > **errp);
> > +
> > +struct IGVMDirectiveHandler {
> > +    uint32_t type;
> > +    int (*handler)(ConfidentialGuestSupport *cgs, int i,
> > +                   uint32_t compatibility_mask, const uint8_t *header_data,
> > +                   Error **errp);
> > +};
> > +
> > +static struct IGVMDirectiveHandler directive_handlers[] = {
> 
> const.
> 
> > +    { IGVM_VHT_PAGE_DATA, directive_page_data },
> > +    { IGVM_VHT_VP_CONTEXT, directive_vp_context },
> > +    { IGVM_VHT_PARAMETER_AREA, directive_parameter_area },
> > +    { IGVM_VHT_PARAMETER_INSERT, directive_parameter_insert },
> > +    { IGVM_VHT_MEMORY_MAP, directive_memory_map },
> > +    { IGVM_VHT_VP_COUNT_PARAMETER, directive_vp_count },
> > +    { IGVM_VHT_ENVIRONMENT_INFO_PARAMETER, directive_environment_info },
> > +    { IGVM_VHT_REQUIRED_MEMORY, directive_required_memory },
> > +};
> > +
> > +static int directive(uint32_t type, ConfidentialGuestSupport *cgs, int i,
> > +                      uint32_t compatibility_mask, Error **errp)
> > +{
> > +    size_t handler;
> > +    IgvmHandle header_handle;
> > +    const uint8_t *header_data;
> > +    int result;
> > +
> > +    for (handler = 0; handler < (sizeof(directive_handlers) /
> > +                                 sizeof(struct IGVMDirectiveHandler));
> 
> We have ARRAY_SIZE(), which is easier to read.
Noted.

> 
> > +         ++handler) {
> > +        if (directive_handlers[handler].type == type) {
> > +            header_handle =
> > +                igvm_get_header(cgs->igvm, HEADER_SECTION_DIRECTIVE, i);
> > +            if (header_handle < 0) {
> > +                error_setg(
> > +                    errp,
> > +                    "IGVM file is invalid: Failed to read directive header
> > (code: %d)",
> > +                    (int)header_handle);
> > +                return -1;
> > +            }
> > +            header_data = igvm_get_buffer(cgs->igvm, header_handle) +
> > +                          sizeof(IGVM_VHS_VARIABLE_HEADER);
> > +            result = directive_handlers[handler].handler(
> > +                cgs, i, compatibility_mask, header_data, errp);
> > +            igvm_free_buffer(cgs->igvm, header_handle);
> > +            return result;
> > +        }
> > +    }
> > +    error_setg(errp,
> > +               "IGVM: Unknown directive type encountered when processing
> > file: "
> > +               "(type 0x%X)",
> > +               type);
> > +    return -1;
> > +}
> 
> [...]
> 
> > +int igvm_process(ConfidentialGuestSupport *cgs, Error **errp)
> > +{
> > +    int32_t result;
> > +    int i;
> 
> Since 'i' is never set with a negative value, it can be declared
> as unsigned.
> 
> > +    uint32_t compatibility_mask;
> > +    IgvmParameterData *parameter;
> > +    int retval = 0;
> > +
> > +    /*
> > +     * If this is not a Confidential guest or no IGVM has been provided
> > then
> > +     * this is a no-op.
> > +     */
> > +    if (!cgs->igvm) {
> > +        return 0;
> > +    }
> > +
> > +    /*
> > +     * Check that the IGVM file provides configuration for the current
> > +     * platform
> > +     */
> > +    compatibility_mask = supported_platform_compat_mask(cgs, errp);
> > +    if (compatibility_mask == 0) {
> > +        return -1;
> > +    }
> > +
> > +    result = igvm_header_count(cgs->igvm, HEADER_SECTION_DIRECTIVE);
> > +    if (result < 0) {
> > +        error_setg(
> > +            errp, "Invalid directive header count in IGVM file. Error code:
> > %X",
> > +            result);
> > +        return -1;
> > +    }
> > +
> > +    QTAILQ_INIT(&parameter_data);
> > +
> > +    for (i = 0; i < (int)result; ++i) {
> 
> Well, 'i' is clearly unsigned.
> 
> I'd rename s/result/header_count/ and s/i/header_index/ here and in all
> the callees.
> 
Ok. I'm also going to move what was 'i' but represents the current header index
into the new QemuIgvm context structure as that is being passed around to all
the handlers.

> > +        IgvmVariableHeaderType type =
> > +            igvm_get_header_type(cgs->igvm, HEADER_SECTION_DIRECTIVE, i);
> > +        if (directive(type, cgs, i, compatibility_mask, errp) < 0) {
> > +            retval = -1;
> > +            break;
> > +        }
> > +    }
> > +
> > +    /*
> > +     * Contiguous pages of data with compatible flags are grouped together
> > in
> > +     * order to reduce the number of memory regions we create. Make sure
> > the
> > +     * last group is processed with this call.
> > +     */
> > +    if (retval == 0) {
> > +        retval = process_mem_page(cgs, i, NULL, errp);
> > +    }
> > +
> > +    QTAILQ_FOREACH(parameter, &parameter_data, next)
> > +    {
> > +        g_free(parameter->data);
> > +        parameter->data = NULL;
> > +    }
> > +
> > +    return retval;
> > +}
> > +
> > +#endif
> > diff --git a/backends/meson.build b/backends/meson.build
> > index d550ac19f7..d092850a07 100644
> > --- a/backends/meson.build
> > +++ b/backends/meson.build
> > @@ -32,6 +32,7 @@ system_ss.add(when: gio, if_true: files('dbus-vmstate.c'))
> >   system_ss.add(when: 'CONFIG_SGX', if_true: files('hostmem-epc.c'))
> >   if igvm.found()
> >     system_ss.add(igvm)
> > +  system_ss.add(files('igvm.c'))
> 
> You want in the same line to propagate the library flags to the built
> objects:
> 
>      system_ss.add([files('igvm.c'), igvm])
> 
Ok.

> >   endif
> >   
> >   subdir('tpm')
> > diff --git a/include/exec/confidential-guest-support.h
> > b/include/exec/confidential-guest-support.h
> > index a8ad84fa07..9419e91249 100644
> > --- a/include/exec/confidential-guest-support.h
> > +++ b/include/exec/confidential-guest-support.h
> > @@ -27,6 +27,10 @@
> >   #include "igvm/igvm.h"
> >   #endif
> >   
> > +#if defined(CONFIG_IGVM)
> > +#include "igvm/igvm.h"
> 
> You already included it in the previous commit ;)
> 
> > +#endif
> > +
> >   #define TYPE_CONFIDENTIAL_GUEST_SUPPORT "confidential-guest-support"
> >   OBJECT_DECLARE_SIMPLE_TYPE(ConfidentialGuestSupport,
> > CONFIDENTIAL_GUEST_SUPPORT)
> >   
> > @@ -93,6 +97,7 @@ struct ConfidentialGuestSupport {
> >        *                Virtual Machine (IGVM) format.
> >        */
> >       char *igvm_filename;
> > +    IgvmHandle igvm;
> >   #endif
> >   
> >       /*
> > diff --git a/include/exec/igvm.h b/include/exec/igvm.h
> > new file mode 100644
> > index 0000000000..59594f047e
> > --- /dev/null
> > +++ b/include/exec/igvm.h
> 
> Please move to include/sysemu/ (confidential-guest-support.h will soon
> be moved there).
> 
Do you mean just the header file? Is backends/igvm.c the correct location?

> > @@ -0,0 +1,36 @@
> > +/*
> > + * QEMU IGVM configuration backend for Confidential Guests
> > + *
> > + * Copyright (C) 2023-2024 SUSE
> > + *
> > + * Authors:
> > + *  Roy Hopkins <roy.hopkins@suse.com>
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2 or
> > later.
> > + * See the COPYING file in the top-level directory.
> > + */
> > +
> > +#ifndef EXEC_IGVM_H
> > +#define EXEC_IGVM_H
> > +
> > +#include "exec/confidential-guest-support.h"
> > +
> > +#if defined(CONFIG_IGVM)
> > +
> > +int igvm_file_init(ConfidentialGuestSupport *cgs, Error **errp);
> > +int igvm_process(ConfidentialGuestSupport *cgs, Error **erp);
> > +
> > +#else
> > +
> > +static inline int igvm_file_init(ConfidentialGuestSupport *cgs, Error
> > **errp)
> > +{
> > +    return 0;
> > +}
> > +
> > +static inline int igvm_process(ConfidentialGuestSupport *cgs, Error **errp)
> > +{
> > +}
> > +
> > +#endif
> > +
> > +#endif
> 
Thanks for the reviews.

I'll be addressing all the above comments that I haven't explicitly commented on
in the next version of the patch series. Thanks.

Regards,
Roy


  reply	other threads:[~2024-05-07 14:20 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <cover.1712141833.git.roy.hopkins@suse.com>
2024-04-03 11:11 ` [PATCH v2 01/10] meson: Add optional dependency on IGVM library Roy Hopkins
2024-04-16 14:13   ` Daniel P. Berrangé
2024-05-01  8:53     ` Roy Hopkins
2024-04-03 11:11 ` [PATCH v2 02/10] backends/confidential-guest-support: Add IGVM file parameter Roy Hopkins
2024-04-16 13:29   ` Daniel P. Berrangé
2024-04-03 11:11 ` [PATCH v2 03/10] backends/confidential-guest-support: Add functions to support IGVM Roy Hopkins
2024-04-04  8:00   ` Philippe Mathieu-Daudé
2024-04-16 13:31     ` Daniel P. Berrangé
2024-05-07 14:08       ` Roy Hopkins
2024-04-03 11:11 ` [PATCH v2 04/10] backends/igvm: Implement parsing and processing of IGVM files Roy Hopkins
2024-04-04  7:58   ` Philippe Mathieu-Daudé
2024-05-07 14:19     ` Roy Hopkins [this message]
2024-04-16 14:05   ` Daniel P. Berrangé
2024-05-07 14:25     ` Roy Hopkins
2024-04-03 11:11 ` [PATCH v2 05/10] i386/pc: Process IGVM file during PC initialization if present Roy Hopkins
2024-04-16 14:19   ` Daniel P. Berrangé
2024-04-03 11:11 ` [PATCH v2 06/10] i386/pc_sysfw: Ensure sysfw flash configuration does not conflict with IGVM Roy Hopkins
2024-04-04 12:36   ` Ani Sinha
2024-05-07 14:32     ` Roy Hopkins
2024-04-03 11:11 ` [PATCH v2 07/10] i386/sev: Refactor setting of reset vector and initial CPU state Roy Hopkins
2024-04-03 11:11 ` [PATCH v2 08/10] i386/sev: Implement ConfidentialGuestSupport functions for SEV Roy Hopkins
2024-04-16 14:30   ` Daniel P. Berrangé
2024-05-07 14:34     ` Roy Hopkins
2024-04-03 11:11 ` [PATCH v2 09/10] docs/system: Add documentation on support for IGVM Roy Hopkins
2024-04-03 11:11 ` [PATCH v2 10/10] docs/interop/firmware.json: Add igvm to FirmwareDevice Roy Hopkins

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