[Qemu-devel] [RFC PATCH 0/4] pc: Support firmware configuration with -blockdev (splitted)

[Qemu-devel] [RFC PATCH 0/4] pc: Support firmware configuration with -blockdev (splitted)

[Philippe Mathieu-Daudé]

While reviewing Markus' series [*] I splitted the last patch (6/6) to
understand it better.

[*] https://lists.gnu.org/archive/html/qemu-devel/2019-02/msg06798.html

Based-on: <20190225183757.27378-6-armbru@redhat.com>

Markus Armbruster (1):
  pc: Support firmware configuration with -blockdev

Philippe Mathieu-Daudé (3):
  pflash_cfi01: Add pflash_cfi01_get_blk() helper
  hw/i386/pc_sysfw: Remove obsolete PcSysFwDevice
  hw/i386/pc_sysfw: Let pc_system_firmware_init() access PCMachineState

 hw/block/pflash_cfi01.c  |   5 +
 hw/i386/pc.c             |   4 +-
 hw/i386/pc_sysfw.c       | 232 +++++++++++++++++++++++++--------------
 include/hw/block/flash.h |   1 +
 include/hw/i386/pc.h     |   6 +-
 5 files changed, 164 insertions(+), 84 deletions(-)

-- 
2.20.1

[Qemu-devel] [PATCH 1/4] pflash_cfi01: Add pflash_cfi01_get_blk() helper

[Philippe Mathieu-Daudé]

Add an helper to access the opaque struct PFlashCFI01.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
[PMD: Extracted from bigger patch]
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 hw/block/pflash_cfi01.c  | 5 +++++
 include/hw/block/flash.h | 1 +
 2 files changed, 6 insertions(+)

diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
index 9d1c356eb6..9ecab693e8 100644
--- a/hw/block/pflash_cfi01.c
+++ b/hw/block/pflash_cfi01.c
@@ -972,6 +972,11 @@ MemoryRegion *pflash_cfi01_get_memory(PFlashCFI01 *fl)
     return &fl->mem;
 }
 
+BlockBackend *pflash_cfi01_get_blk(PFlashCFI01 *fl)
+{
+    return fl->blk;
+}
+
 static void postload_update_cb(void *opaque, int running, RunState state)
 {
     PFlashCFI01 *pfl = opaque;
diff --git a/include/hw/block/flash.h b/include/hw/block/flash.h
index 914932eaec..a0f488732a 100644
--- a/include/hw/block/flash.h
+++ b/include/hw/block/flash.h
@@ -22,6 +22,7 @@ PFlashCFI01 *pflash_cfi01_register(hwaddr base,
                                    uint16_t id0, uint16_t id1,
                                    uint16_t id2, uint16_t id3,
                                    int be);
+BlockBackend *pflash_cfi01_get_blk(PFlashCFI01 *fl);
 MemoryRegion *pflash_cfi01_get_memory(PFlashCFI01 *fl);
 
 /* pflash_cfi02.c */
-- 
2.20.1

Re: [Qemu-devel] [PATCH 1/4] pflash_cfi01: Add pflash_cfi01_get_blk() helper

[Laszlo Ersek]

On 03/04/19 20:48, Philippe Mathieu-Daudé wrote:
> Add an helper to access the opaque struct PFlashCFI01.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> [PMD: Extracted from bigger patch]
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  hw/block/pflash_cfi01.c  | 5 +++++
>  include/hw/block/flash.h | 1 +
>  2 files changed, 6 insertions(+)
> 
> diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
> index 9d1c356eb6..9ecab693e8 100644
> --- a/hw/block/pflash_cfi01.c
> +++ b/hw/block/pflash_cfi01.c
> @@ -972,6 +972,11 @@ MemoryRegion *pflash_cfi01_get_memory(PFlashCFI01 *fl)
>      return &fl->mem;
>  }
>  
> +BlockBackend *pflash_cfi01_get_blk(PFlashCFI01 *fl)
> +{
> +    return fl->blk;
> +}
> +
>  static void postload_update_cb(void *opaque, int running, RunState state)
>  {
>      PFlashCFI01 *pfl = opaque;
> diff --git a/include/hw/block/flash.h b/include/hw/block/flash.h
> index 914932eaec..a0f488732a 100644
> --- a/include/hw/block/flash.h
> +++ b/include/hw/block/flash.h
> @@ -22,6 +22,7 @@ PFlashCFI01 *pflash_cfi01_register(hwaddr base,
>                                     uint16_t id0, uint16_t id1,
>                                     uint16_t id2, uint16_t id3,
>                                     int be);
> +BlockBackend *pflash_cfi01_get_blk(PFlashCFI01 *fl);
>  MemoryRegion *pflash_cfi01_get_memory(PFlashCFI01 *fl);
>  
>  /* pflash_cfi02.c */
> 

I generally prefer to keep the same order between declarations of
functions, and definitions of the same functions. Compare
pflash_cfi01_get_memory() here.

With that updated,

Reviewed-by: Laszlo Ersek <lersek@redhat.com>


Thanks
Laszlo

Re: [Qemu-devel] [PATCH 1/4] pflash_cfi01: Add pflash_cfi01_get_blk() helper

[Markus Armbruster]

Laszlo Ersek <lersek@redhat.com> writes:

> On 03/04/19 20:48, Philippe Mathieu-Daudé wrote:
>> Add an helper to access the opaque struct PFlashCFI01.
>> 
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> [PMD: Extracted from bigger patch]
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> ---
>>  hw/block/pflash_cfi01.c  | 5 +++++
>>  include/hw/block/flash.h | 1 +
>>  2 files changed, 6 insertions(+)
>> 
>> diff --git a/hw/block/pflash_cfi01.c b/hw/block/pflash_cfi01.c
>> index 9d1c356eb6..9ecab693e8 100644
>> --- a/hw/block/pflash_cfi01.c
>> +++ b/hw/block/pflash_cfi01.c
>> @@ -972,6 +972,11 @@ MemoryRegion *pflash_cfi01_get_memory(PFlashCFI01 *fl)
>>      return &fl->mem;
>>  }
>>  
>> +BlockBackend *pflash_cfi01_get_blk(PFlashCFI01 *fl)
>> +{
>> +    return fl->blk;
>> +}
>> +
>>  static void postload_update_cb(void *opaque, int running, RunState state)
>>  {
>>      PFlashCFI01 *pfl = opaque;
>> diff --git a/include/hw/block/flash.h b/include/hw/block/flash.h
>> index 914932eaec..a0f488732a 100644
>> --- a/include/hw/block/flash.h
>> +++ b/include/hw/block/flash.h
>> @@ -22,6 +22,7 @@ PFlashCFI01 *pflash_cfi01_register(hwaddr base,
>>                                     uint16_t id0, uint16_t id1,
>>                                     uint16_t id2, uint16_t id3,
>>                                     int be);
>> +BlockBackend *pflash_cfi01_get_blk(PFlashCFI01 *fl);
>>  MemoryRegion *pflash_cfi01_get_memory(PFlashCFI01 *fl);
>>  
>>  /* pflash_cfi02.c */
>> 
>
> I generally prefer to keep the same order between declarations of
> functions, and definitions of the same functions. Compare
> pflash_cfi01_get_memory() here.

My fault, not Philippe's.

> With that updated,
>
> Reviewed-by: Laszlo Ersek <lersek@redhat.com>

Thanks!

[Qemu-devel] [PATCH 2/4] hw/i386/pc_sysfw: Remove obsolete PcSysFwDevice

[Philippe Mathieu-Daudé]

This structure is not used since 6dd2a5c98a.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 hw/i386/pc_sysfw.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c
index 34727c5b1f..46b87afe23 100644
--- a/hw/i386/pc_sysfw.c
+++ b/hw/i386/pc_sysfw.c
@@ -40,11 +40,6 @@
 
 #define BIOS_FILENAME "bios.bin"
 
-typedef struct PcSysFwDevice {
-    SysBusDevice busdev;
-    uint8_t isapc_ram_fw;
-} PcSysFwDevice;
-
 static void pc_isa_bios_init(MemoryRegion *rom_memory,
                              MemoryRegion *flash_mem,
                              int ram_size)
-- 
2.20.1

Re: [Qemu-devel] [PATCH 2/4] hw/i386/pc_sysfw: Remove obsolete PcSysFwDevice

[Laszlo Ersek]

On 03/04/19 20:48, Philippe Mathieu-Daudé wrote:
> This structure is not used since 6dd2a5c98a.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  hw/i386/pc_sysfw.c | 5 -----
>  1 file changed, 5 deletions(-)
> 
> diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c
> index 34727c5b1f..46b87afe23 100644
> --- a/hw/i386/pc_sysfw.c
> +++ b/hw/i386/pc_sysfw.c
> @@ -40,11 +40,6 @@
>  
>  #define BIOS_FILENAME "bios.bin"
>  
> -typedef struct PcSysFwDevice {
> -    SysBusDevice busdev;
> -    uint8_t isapc_ram_fw;
> -} PcSysFwDevice;
> -
>  static void pc_isa_bios_init(MemoryRegion *rom_memory,
>                               MemoryRegion *flash_mem,
>                               int ram_size)
> 

Looks sane, and the commit reference is precise.

Reviewed-by: Laszlo Ersek <lersek@redhat.com>

Thanks
Laszlo

[Qemu-devel] [PATCH 3/4] hw/i386/pc_sysfw: Let pc_system_firmware_init() access PCMachineState

[Philippe Mathieu-Daudé]

PCMachineState will be used in the next patch.
Since We can access PCMachineClass from it, directly use it.
We can also access pcmc->pci_enabled, remove the isapc_ram_fw
argument.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
[PMD: Extracted from bigger patch]
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 hw/i386/pc.c         | 2 +-
 hw/i386/pc_sysfw.c   | 8 +++++---
 include/hw/i386/pc.h | 3 +--
 3 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 3889eccdc3..3cd8ed1794 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1830,7 +1830,7 @@ void pc_memory_init(PCMachineState *pcms,
     }
 
     /* Initialize PC system firmware */
-    pc_system_firmware_init(rom_memory, !pcmc->pci_enabled);
+    pc_system_firmware_init(pcms, rom_memory);
 
     option_rom_mr = g_malloc(sizeof(*option_rom_mr));
     memory_region_init_ram(option_rom_mr, NULL, "pc.rom", PC_ROM_SIZE,
diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c
index 46b87afe23..55a3c563df 100644
--- a/hw/i386/pc_sysfw.c
+++ b/hw/i386/pc_sysfw.c
@@ -231,15 +231,17 @@ static void old_pc_system_rom_init(MemoryRegion *rom_memory, bool isapc_ram_fw)
                                 bios);
 }
 
-void pc_system_firmware_init(MemoryRegion *rom_memory, bool isapc_ram_fw)
+void pc_system_firmware_init(PCMachineState *pcms,
+                             MemoryRegion *rom_memory)
 {
+    PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
     DriveInfo *pflash_drv;
 
     pflash_drv = drive_get(IF_PFLASH, 0, 0);
 
-    if (isapc_ram_fw || pflash_drv == NULL) {
+    if (!pcmc->pci_enabled || pflash_drv == NULL) {
         /* When a pflash drive is not found, use rom-mode */
-        old_pc_system_rom_init(rom_memory, isapc_ram_fw);
+        old_pc_system_rom_init(rom_memory, true);
         return;
     }
 
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 3ff127ebd0..eb7360feac 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -278,8 +278,7 @@ extern PCIDevice *piix4_dev;
 int piix4_init(PCIBus *bus, ISABus **isa_bus, int devfn);
 
 /* pc_sysfw.c */
-void pc_system_firmware_init(MemoryRegion *rom_memory,
-                             bool isapc_ram_fw);
+void pc_system_firmware_init(PCMachineState *pcms, MemoryRegion *rom_memory);
 
 /* acpi-build.c */
 void pc_madt_cpu_entry(AcpiDeviceIf *adev, int uid,
-- 
2.20.1

Re: [Qemu-devel] [PATCH 3/4] hw/i386/pc_sysfw: Let pc_system_firmware_init() access PCMachineState

[Laszlo Ersek]

On 03/04/19 20:48, Philippe Mathieu-Daudé wrote:
> PCMachineState will be used in the next patch.
> Since We can access PCMachineClass from it, directly use it.
> We can also access pcmc->pci_enabled, remove the isapc_ram_fw
> argument.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> [PMD: Extracted from bigger patch]
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  hw/i386/pc.c         | 2 +-
>  hw/i386/pc_sysfw.c   | 8 +++++---
>  include/hw/i386/pc.h | 3 +--
>  3 files changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 3889eccdc3..3cd8ed1794 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1830,7 +1830,7 @@ void pc_memory_init(PCMachineState *pcms,
>      }
>  
>      /* Initialize PC system firmware */
> -    pc_system_firmware_init(rom_memory, !pcmc->pci_enabled);
> +    pc_system_firmware_init(pcms, rom_memory);
>  
>      option_rom_mr = g_malloc(sizeof(*option_rom_mr));
>      memory_region_init_ram(option_rom_mr, NULL, "pc.rom", PC_ROM_SIZE,
> diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c
> index 46b87afe23..55a3c563df 100644
> --- a/hw/i386/pc_sysfw.c
> +++ b/hw/i386/pc_sysfw.c
> @@ -231,15 +231,17 @@ static void old_pc_system_rom_init(MemoryRegion *rom_memory, bool isapc_ram_fw)
>                                  bios);
>  }
>  
> -void pc_system_firmware_init(MemoryRegion *rom_memory, bool isapc_ram_fw)
> +void pc_system_firmware_init(PCMachineState *pcms,
> +                             MemoryRegion *rom_memory)
>  {
> +    PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
>      DriveInfo *pflash_drv;
>  
>      pflash_drv = drive_get(IF_PFLASH, 0, 0);
>  
> -    if (isapc_ram_fw || pflash_drv == NULL) {
> +    if (!pcmc->pci_enabled || pflash_drv == NULL) {
>          /* When a pflash drive is not found, use rom-mode */
> -        old_pc_system_rom_init(rom_memory, isapc_ram_fw);
> +        old_pc_system_rom_init(rom_memory, true);
>          return;
>      }
>  

This code extraction (as a pure refactoring) is incorrect.

In Markus's patch at
<https://lists.gnu.org/archive/html/qemu-devel/2019-02/msg06804.html>,
the condition that guards the old_pc_system_rom_init() call loses one
half of the disjunction:

-    if (isapc_ram_fw || pflash_drv == NULL) {
+    if (!pcmc->pci_enabled) {

namely the "pflash_drv == NULL" sub-condition. Therefore the
old_pc_system_rom_init() call can hardwire the second argument as "true":

-        old_pc_system_rom_init(rom_memory, isapc_ram_fw);
+        old_pc_system_rom_init(rom_memory, true);

However, in this refactoring, the (pflash_drv == NULL) subcondition is
not deleted; only the original condition is expressed differently.
Therefore we can't replace the "isapc_ram_fw" argument of
old_pc_system_rom_init() with plain "true", we have to use
"!pcmc->pci_enabled" instead.

However, if we write down "!pcmc->pci_enabled" twice for this purpose,
then it becomes too complex to read (for me anyway). So in that case I'd
even suggest keeping the "isapc_ram_fw" local variable, just turn it
into a normal local variable rather than take it as a parameter.

In the next patch, "isapc_ram_fw" can be killed just the same.

Thanks
Laszlo

> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> index 3ff127ebd0..eb7360feac 100644
> --- a/include/hw/i386/pc.h
> +++ b/include/hw/i386/pc.h
> @@ -278,8 +278,7 @@ extern PCIDevice *piix4_dev;
>  int piix4_init(PCIBus *bus, ISABus **isa_bus, int devfn);
>  
>  /* pc_sysfw.c */
> -void pc_system_firmware_init(MemoryRegion *rom_memory,
> -                             bool isapc_ram_fw);
> +void pc_system_firmware_init(PCMachineState *pcms, MemoryRegion *rom_memory);
>  
>  /* acpi-build.c */
>  void pc_madt_cpu_entry(AcpiDeviceIf *adev, int uid,
> 

Re: [Qemu-devel] [PATCH 3/4] hw/i386/pc_sysfw: Let pc_system_firmware_init() access PCMachineState

[Markus Armbruster]

Laszlo Ersek <lersek@redhat.com> writes:

> On 03/04/19 20:48, Philippe Mathieu-Daudé wrote:
>> PCMachineState will be used in the next patch.
>> Since We can access PCMachineClass from it, directly use it.
>> We can also access pcmc->pci_enabled, remove the isapc_ram_fw
>> argument.
>> 
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> [PMD: Extracted from bigger patch]
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> ---
>>  hw/i386/pc.c         | 2 +-
>>  hw/i386/pc_sysfw.c   | 8 +++++---
>>  include/hw/i386/pc.h | 3 +--
>>  3 files changed, 7 insertions(+), 6 deletions(-)
>> 
>> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
>> index 3889eccdc3..3cd8ed1794 100644
>> --- a/hw/i386/pc.c
>> +++ b/hw/i386/pc.c
>> @@ -1830,7 +1830,7 @@ void pc_memory_init(PCMachineState *pcms,
>>      }
>>  
>>      /* Initialize PC system firmware */
>> -    pc_system_firmware_init(rom_memory, !pcmc->pci_enabled);
>> +    pc_system_firmware_init(pcms, rom_memory);
>>  
>>      option_rom_mr = g_malloc(sizeof(*option_rom_mr));
>>      memory_region_init_ram(option_rom_mr, NULL, "pc.rom", PC_ROM_SIZE,
>> diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c
>> index 46b87afe23..55a3c563df 100644
>> --- a/hw/i386/pc_sysfw.c
>> +++ b/hw/i386/pc_sysfw.c
>> @@ -231,15 +231,17 @@ static void old_pc_system_rom_init(MemoryRegion *rom_memory, bool isapc_ram_fw)
>>                                  bios);
>>  }
>>  
>> -void pc_system_firmware_init(MemoryRegion *rom_memory, bool isapc_ram_fw)
>> +void pc_system_firmware_init(PCMachineState *pcms,
>> +                             MemoryRegion *rom_memory)
>>  {
>> +    PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
>>      DriveInfo *pflash_drv;
>>  
>>      pflash_drv = drive_get(IF_PFLASH, 0, 0);
>>  
>> -    if (isapc_ram_fw || pflash_drv == NULL) {
>> +    if (!pcmc->pci_enabled || pflash_drv == NULL) {
>>          /* When a pflash drive is not found, use rom-mode */
>> -        old_pc_system_rom_init(rom_memory, isapc_ram_fw);
>> +        old_pc_system_rom_init(rom_memory, true);
>>          return;
>>      }
>>  
>
> This code extraction (as a pure refactoring) is incorrect.
>
> In Markus's patch at
> <https://lists.gnu.org/archive/html/qemu-devel/2019-02/msg06804.html>,
> the condition that guards the old_pc_system_rom_init() call loses one
> half of the disjunction:
>
> -    if (isapc_ram_fw || pflash_drv == NULL) {
> +    if (!pcmc->pci_enabled) {
>
> namely the "pflash_drv == NULL" sub-condition. Therefore the
> old_pc_system_rom_init() call can hardwire the second argument as "true":
>
> -        old_pc_system_rom_init(rom_memory, isapc_ram_fw);
> +        old_pc_system_rom_init(rom_memory, true);
>
> However, in this refactoring, the (pflash_drv == NULL) subcondition is
> not deleted; only the original condition is expressed differently.
> Therefore we can't replace the "isapc_ram_fw" argument of
> old_pc_system_rom_init() with plain "true", we have to use
> "!pcmc->pci_enabled" instead.

You're right

> However, if we write down "!pcmc->pci_enabled" twice for this purpose,
> then it becomes too complex to read (for me anyway). So in that case I'd
> even suggest keeping the "isapc_ram_fw" local variable, just turn it
> into a normal local variable rather than take it as a parameter.
>
> In the next patch, "isapc_ram_fw" can be killed just the same.

I'm doing that in my tree now.  Thanks!

[Qemu-devel] [RFC PATCH 4/4] pc: Support firmware configuration with -blockdev

[Philippe Mathieu-Daudé]

From: Markus Armbruster <armbru@redhat.com>

The PC machines put firmware in ROM by default.  To get it put into
flash memory (required by OVMF), you have to use -drive
if=pflash,unit=0,... and optionally -drive if=pflash,unit=1,...

Why two -drive?  This permits setting up one part of the flash memory
read-only, and the other part read/write.  Below the hood, it creates
two separate flash devices, because we were too lazy to improve our
flash device models to support sector protection.

The problem at hand is to do the same with -blockdev somehow, as one
more step towards deprecating -drive.

Mapping -drive if=none,... to -blockdev is a solved problem.  With
if=T other than if=none, -drive additionally configures a block device
frontend.  For non-onboard devices, that part maps to -device.  Also a
solved problem.  For onboard devices such as PC flash memory, we have
an unsolved problem.

This is actually an instance of a wider problem: our general device
configuration interface doesn't cover onboard devices.  Instead, we
have a zoo of ad hoc interfaces that are much more limited.  Some of
them we'd rather deprecate (-drive, -net), but can't until we have
suitable replacements.

Sadly, I can't attack the wider problem today.  So back to the narrow
problem.

My first idea was to reduce it to its solved buddy by using pluggable
instead of onboard devices for the flash memory.  Workable, but it
requires some extra smarts in firmware descriptors and libvirt.  Paolo
had an idea that is simpler for libvirt: keep the devices onboard, and
add machine properties for their block backends.

The implementation is less than straightforward, I'm afraid.

First, block backend properties are *qdev* properties.  Machines can't
have those, as they're not devices.  I could duplicate these qdev
properties as QOM properties, but I hate that.

More seriously, the properties do not belong to the machine, they
belong to the onboard flash devices.  Adding them to the machine would
then require bad magic to somehow transfer them to the flash devices.
Fortunately, QOM provides the means to handle exactly this case: add
alias properties to the machine that forward to the onboard devices'
properties.

Properties need to be created in .instance_init() methods.  For PC
machines, that's pc_machine_initfn().  To make alias properties work,
we need to create the onboard flash devices there, too.  Requires
several bug fixes, in the previous commits.  We also have to realize
the devices.  More on that below.

If the user sets pflash0, firmware resides in flash memory.
pc_system_firmware_init() maps and realizes the flash devices.

Else, firmware resides in ROM.  The onboard flash devices aren't used
then.  pc_system_firmware_init() destroys them unrealized, along with
the alias properties.  Except I can't figure out how to destroy the
devices correctly.  Marked FIXME.

The existing code to pick up drives defined with -drive if=pflash is
replaced by code to desugar into the machine properties.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[PMD: rebased on 'pflash: Fixes and cleanups'
      replaced CFI_PFLASH01 -> PFLASH_CFI01]
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
I included the hack in pc_system_flash_cleanup_unused()
from <87bm2qzfyn.fsf@dusky.pond.sub.org>:
https://lists.gnu.org/archive/html/qemu-devel/2019-03/msg00759.html

 hw/i386/pc.c         |   2 +
 hw/i386/pc_sysfw.c   | 221 ++++++++++++++++++++++++++++---------------
 include/hw/i386/pc.h |   3 +
 3 files changed, 152 insertions(+), 74 deletions(-)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 3cd8ed1794..420a0c5c9e 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -2671,6 +2671,8 @@ static void pc_machine_initfn(Object *obj)
     pcms->smbus_enabled = true;
     pcms->sata_enabled = true;
     pcms->pit_enabled = true;
+
+    pc_system_flash_create(pcms);
 }
 
 static void pc_machine_reset(void)
diff --git a/hw/i386/pc_sysfw.c b/hw/i386/pc_sysfw.c
index 55a3c563df..40d935da21 100644
--- a/hw/i386/pc_sysfw.c
+++ b/hw/i386/pc_sysfw.c
@@ -71,7 +71,53 @@ static void pc_isa_bios_init(MemoryRegion *rom_memory,
     memory_region_set_readonly(isa_bios, true);
 }
 
-#define FLASH_MAP_UNIT_MAX 2
+static PFlashCFI01 *pc_pflash_create(const char *name)
+{
+    DeviceState *dev = qdev_create(NULL, TYPE_PFLASH_CFI01);
+
+    qdev_prop_set_uint64(dev, "sector-length", 4096);
+    qdev_prop_set_uint8(dev, "width", 1);
+    qdev_prop_set_string(dev, "name", name);
+    return PFLASH_CFI01(dev);
+}
+
+void pc_system_flash_create(PCMachineState *pcms)
+{
+    PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
+
+    if (pcmc->pci_enabled) {
+        pcms->flash[0] = pc_pflash_create("system.flash0");
+        pcms->flash[1] = pc_pflash_create("system.flash1");
+        object_property_add_alias(OBJECT(pcms), "pflash0",
+                                  OBJECT(pcms->flash[0]), "drive",
+                                  &error_abort);
+        object_property_add_alias(OBJECT(pcms), "pflash1",
+                                  OBJECT(pcms->flash[1]), "drive",
+                                  &error_abort);
+    }
+}
+
+static void pc_system_flash_cleanup_unused(PCMachineState *pcms)
+{
+    char *prop_name;
+    int i;
+    Object *dev_obj;
+
+    assert(PC_MACHINE_GET_CLASS(pcms)->pci_enabled);
+
+    for (i = 0; i < ARRAY_SIZE(pcms->flash); i++) {
+        dev_obj = OBJECT(pcms->flash[i]);
+        if (!object_property_get_bool(dev_obj, "realized", &error_abort)) {
+            prop_name = g_strdup_printf("pflash%d", i);
+            object_property_del(OBJECT(pcms), prop_name, &error_abort);
+            g_free(prop_name);
+            object_ref(dev_obj);
+            object_get_class(dev_obj)->unparent(dev_obj);
+            object_unref(dev_obj);
+            pcms->flash[i] = NULL;
+        }
+    }
+}
 
 /* We don't have a theoretically justifiable exact lower bound on the base
  * address of any flash mapping. In practice, the IO-APIC MMIO range is
@@ -79,88 +125,78 @@ static void pc_isa_bios_init(MemoryRegion *rom_memory,
  * only 18MB-4KB below 4G. For now, restrict the cumulative mapping to 8MB in
  * size.
  */
-#define FLASH_MAP_BASE_MIN ((hwaddr)(4 * GiB - 8 * MiB))
+#define FLASH_SIZE_LIMIT (8 * MiB)
 
-/* This function maps flash drives from 4G downward, in order of their unit
- * numbers. The mapping starts at unit#0, with unit number increments of 1, and
- * stops before the first missing flash drive, or before
- * unit#FLASH_MAP_UNIT_MAX, whichever is reached first.
- *
- * Addressing within one flash drive is of course not reversed.
- *
- * An error message is printed and the process exits if:
- * - the size of the backing file for a flash drive is non-positive, or not a
- *   multiple of the required sector size, or
- * - the current mapping's base address would fall below FLASH_MAP_BASE_MIN.
+/*
+ * Map the pcms->flash[] from 4GiB downward, and realize.
+ * Map them in descending order, i.e. pcms->flash[0] at the top,
+ * without gaps.
+ * Stop at the first pcms->flash[0] lacking a block backend.
+ * Set each flash's size from its block backend.  Fatal error if the
+ * size isn't a non-zero multiples of 4KiB, or the total size exceeds
+ * FLASH_SIZE_LIMIT.
  *
- * The drive with unit#0 (if available) is mapped at the highest address, and
- * it is passed to pc_isa_bios_init(). Merging several drives for isa-bios is
+ * If pcms->flash[0] has a block backend, its memory is passed to
+ * pc_isa_bios_init().  Merging several flash devices for isa-bios is
  * not supported.
  */
-static void pc_system_flash_init(MemoryRegion *rom_memory)
+static void pc_system_flash_map(PCMachineState *pcms,
+                                MemoryRegion *rom_memory)
 {
-    int unit;
-    DriveInfo *pflash_drv;
+    hwaddr total_size = 0;
+    int i;
     BlockBackend *blk;
     int64_t size;
-    char *fatal_errmsg = NULL;
-    hwaddr phys_addr = 0x100000000ULL;
     uint32_t sector_size = 4096;
     PFlashCFI01 *system_flash;
     MemoryRegion *flash_mem;
-    char name[64];
     void *flash_ptr;
     int ret, flash_size;
 
-    for (unit = 0;
-         (unit < FLASH_MAP_UNIT_MAX &&
-          (pflash_drv = drive_get(IF_PFLASH, 0, unit)) != NULL);
-         ++unit) {
-        blk = blk_by_legacy_dinfo(pflash_drv);
+    assert(PC_MACHINE_GET_CLASS(pcms)->pci_enabled);
+
+    for (i = 0; i < ARRAY_SIZE(pcms->flash); i++) {
+        system_flash = pcms->flash[i];
+        blk = pflash_cfi01_get_blk(system_flash);
+        if (!blk) {
+            break;
+        }
         size = blk_getlength(blk);
         if (size < 0) {
-            fatal_errmsg = g_strdup_printf("failed to get backing file size");
-        } else if (size == 0) {
-            fatal_errmsg = g_strdup_printf("PC system firmware (pflash) "
-                               "cannot have zero size");
-        } else if ((size % sector_size) != 0) {
-            fatal_errmsg = g_strdup_printf("PC system firmware (pflash) "
-                               "must be a multiple of 0x%x", sector_size);
-        } else if (phys_addr < size || phys_addr - size < FLASH_MAP_BASE_MIN) {
-            fatal_errmsg = g_strdup_printf("oversized backing file, pflash "
-                               "segments cannot be mapped under "
-                               TARGET_FMT_plx, FLASH_MAP_BASE_MIN);
+            error_report("can't get size of block device %s: %s",
+                         blk_name(blk), strerror(-size));
+            exit(1);
         }
-        if (fatal_errmsg != NULL) {
-            Location loc;
-
-            /* push a new, "none" location on the location stack; overwrite its
-             * contents with the location saved in the option; print the error
-             * (includes location); pop the top
-             */
-            loc_push_none(&loc);
-            if (pflash_drv->opts != NULL) {
-                qemu_opts_loc_restore(pflash_drv->opts);
-            }
-            error_report("%s", fatal_errmsg);
-            loc_pop(&loc);
-            g_free(fatal_errmsg);
+        if (size == 0) {
+            error_report("system firmware block device %s is empty",
+                         blk_name(blk));
+            exit(1);
+        }
+        if (size == 0 || size % sector_size != 0) {
+            error_report("system firmware block device %s has invalid size "
+                         "%" PRId64,
+                         blk_name(blk), size);
+            info_report("its size must be a non-zero multiple of 0x%x",
+                        sector_size);
+            exit(1);
+        }
+        if ((hwaddr)size != size
+            || total_size > HWADDR_MAX - size
+            || total_size + size > FLASH_SIZE_LIMIT) {
+            error_report("combined size of system firmware exceeds "
+                         "%" PRIu64 " bytes",
+                         FLASH_SIZE_LIMIT);
             exit(1);
         }
 
-        phys_addr -= size;
-
-        /* pflash_cfi01_register() creates a deep copy of the name */
-        snprintf(name, sizeof name, "system.flash%d", unit);
-        system_flash = pflash_cfi01_register(phys_addr, name,
-                                             size, blk, sector_size,
-                                             1      /* width */,
-                                             0x0000 /* id0 */,
-                                             0x0000 /* id1 */,
-                                             0x0000 /* id2 */,
-                                             0x0000 /* id3 */,
-                                             0      /* be */);
-        if (unit == 0) {
+        total_size += size;
+        qdev_prop_set_uint32(DEVICE(system_flash), "num-blocks",
+                             size / sector_size);
+        qdev_init_nofail(DEVICE(system_flash));
+        sysbus_mmio_map(SYS_BUS_DEVICE(system_flash), 0,
+                        0x100000000ULL - total_size);
+
+        if (i == 0) {
             flash_mem = pflash_cfi01_get_memory(system_flash);
             pc_isa_bios_init(rom_memory, flash_mem, size);
 
@@ -235,22 +271,59 @@ void pc_system_firmware_init(PCMachineState *pcms,
                              MemoryRegion *rom_memory)
 {
     PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
+    int i;
     DriveInfo *pflash_drv;
+    BlockBackend *pflash_blk[ARRAY_SIZE(pcms->flash)];
+    Location loc;
 
-    pflash_drv = drive_get(IF_PFLASH, 0, 0);
-
-    if (!pcmc->pci_enabled || pflash_drv == NULL) {
-        /* When a pflash drive is not found, use rom-mode */
+    if (!pcmc->pci_enabled) {
         old_pc_system_rom_init(rom_memory, true);
         return;
     }
 
-    if (kvm_enabled() && !kvm_readonly_mem_enabled()) {
-        /* Older KVM cannot execute from device memory. So, flash memory
-         * cannot be used unless the readonly memory kvm capability is present. */
-        fprintf(stderr, "qemu: pflash with kvm requires KVM readonly memory support\n");
-        exit(1);
+    /* Map legacy -drive if=pflash to machine properties */
+    for (i = 0; i < ARRAY_SIZE(pcms->flash); i++) {
+        pflash_blk[i] = pflash_cfi01_get_blk(pcms->flash[i]);
+        pflash_drv = drive_get(IF_PFLASH, 0, i);
+        if (!pflash_drv) {
+            continue;
+        }
+        loc_push_none(&loc);
+        qemu_opts_loc_restore(pflash_drv->opts);
+        if (pflash_blk[i]) {
+            error_report("clashes with -machine");
+            exit(1);
+        }
+        pflash_blk[i] = blk_by_legacy_dinfo(pflash_drv);
+        qdev_prop_set_drive(DEVICE(pcms->flash[i]),
+                            "drive", pflash_blk[i], &error_fatal);
+        loc_pop(&loc);
+    }
+
+    /* Reject gaps */
+    for (i = 1; i < ARRAY_SIZE(pcms->flash); i++) {
+        if (pflash_blk[i] && !pflash_blk[i - 1]) {
+            error_report("pflash%d requires pflash%d", i, i - 1);
+            exit(1);
+        }
+    }
+
+    if (!pflash_blk[0]) {
+        /* Machine property pflash0 not set, use ROM mode */
+        old_pc_system_rom_init(rom_memory, false);
+    } else {
+        if (kvm_enabled() && !kvm_readonly_mem_enabled()) {
+            /*
+             * Older KVM cannot execute from device memory. So, flash
+             * memory cannot be used unless the readonly memory kvm
+             * capability is present.
+             */
+            error_report("pflash with kvm requires KVM readonly memory support");
+            exit(1);
+        }
+
+        pc_system_flash_map(pcms, rom_memory);
     }
 
-    pc_system_flash_init(rom_memory);
+    pc_system_flash_cleanup_unused(pcms);
 }
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index eb7360feac..266639ca8c 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -6,6 +6,7 @@
 #include "hw/boards.h"
 #include "hw/isa/isa.h"
 #include "hw/block/fdc.h"
+#include "hw/block/flash.h"
 #include "net/net.h"
 #include "hw/i386/ioapic.h"
 
@@ -39,6 +40,7 @@ struct PCMachineState {
     PCIBus *bus;
     FWCfgState *fw_cfg;
     qemu_irq *gsi;
+    PFlashCFI01 *flash[2];
 
     /* Configuration options: */
     uint64_t max_ram_below_4g;
@@ -278,6 +280,7 @@ extern PCIDevice *piix4_dev;
 int piix4_init(PCIBus *bus, ISABus **isa_bus, int devfn);
 
 /* pc_sysfw.c */
+void pc_system_flash_create(PCMachineState *pcms);
 void pc_system_firmware_init(PCMachineState *pcms, MemoryRegion *rom_memory);
 
 /* acpi-build.c */
-- 
2.20.1

Re: [Qemu-devel] [RFC PATCH 4/4] pc: Support firmware configuration with -blockdev

[Laszlo Ersek]

Hi Phil,

On 03/04/19 20:48, Philippe Mathieu-Daudé wrote:

> [PMD: rebased on 'pflash: Fixes and cleanups'
>       replaced CFI_PFLASH01 -> PFLASH_CFI01]

[...]

> -#define FLASH_MAP_UNIT_MAX 2
> +static PFlashCFI01 *pc_pflash_create(const char *name)
> +{
> +    DeviceState *dev = qdev_create(NULL, TYPE_PFLASH_CFI01);
> +
> +    qdev_prop_set_uint64(dev, "sector-length", 4096);

[...]

> -static void pc_system_flash_init(MemoryRegion *rom_memory)
> +static void pc_system_flash_map(PCMachineState *pcms,
> +                                MemoryRegion *rom_memory)
>  {
> -    int unit;
> -    DriveInfo *pflash_drv;
> +    hwaddr total_size = 0;
> +    int i;
>      BlockBackend *blk;
>      int64_t size;
> -    char *fatal_errmsg = NULL;
> -    hwaddr phys_addr = 0x100000000ULL;
>      uint32_t sector_size = 4096;

[...]

> +        if (size == 0) {
> +            error_report("system firmware block device %s is empty",
> +                         blk_name(blk));
> +            exit(1);
> +        }
> +        if (size == 0 || size % sector_size != 0) {

I think you missed my points (1) and (2), and Markus's followup, here:

https://lists.gnu.org/archive/html/qemu-devel/2019-02/msg07018.html

Thanks
Laszlo

Re: [Qemu-devel] [RFC PATCH 4/4] pc: Support firmware configuration with -blockdev

[Philippe Mathieu-Daudé]

Hi Laszlo!

On 3/5/19 6:34 PM, Laszlo Ersek wrote:
> Hi Phil,
> 
> On 03/04/19 20:48, Philippe Mathieu-Daudé wrote:
> 
>> [PMD: rebased on 'pflash: Fixes and cleanups'
>>       replaced CFI_PFLASH01 -> PFLASH_CFI01]
> 
> [...]
> 
>> -#define FLASH_MAP_UNIT_MAX 2
>> +static PFlashCFI01 *pc_pflash_create(const char *name)
>> +{
>> +    DeviceState *dev = qdev_create(NULL, TYPE_PFLASH_CFI01);
>> +
>> +    qdev_prop_set_uint64(dev, "sector-length", 4096);
> 
> [...]
> 
>> -static void pc_system_flash_init(MemoryRegion *rom_memory)
>> +static void pc_system_flash_map(PCMachineState *pcms,
>> +                                MemoryRegion *rom_memory)
>>  {
>> -    int unit;
>> -    DriveInfo *pflash_drv;
>> +    hwaddr total_size = 0;
>> +    int i;
>>      BlockBackend *blk;
>>      int64_t size;
>> -    char *fatal_errmsg = NULL;
>> -    hwaddr phys_addr = 0x100000000ULL;
>>      uint32_t sector_size = 4096;
> 
> [...]
> 
>> +        if (size == 0) {
>> +            error_report("system firmware block device %s is empty",
>> +                         blk_name(blk));
>> +            exit(1);
>> +        }
>> +        if (size == 0 || size % sector_size != 0) {
> 
> I think you missed my points (1) and (2), and Markus's followup, here:
> 
> https://lists.gnu.org/archive/html/qemu-devel/2019-02/msg07018.html

Actually I missed your whole mail...

I'll let Markus take what he likes from this 'splitting' series, and
apply your comments on top if it :)

Markus: you can also drop patches 3/4 of this series if it makes your
work harder.

Thanks both!

Phil.

Re: [Qemu-devel] [RFC PATCH 0/4] pc: Support firmware configuration with -blockdev (splitted)

[Markus Armbruster]

Philippe Mathieu-Daudé <philmd@redhat.com> writes:

> While reviewing Markus' series [*] I splitted the last patch (6/6) to
> understand it better.
>
> [*] https://lists.gnu.org/archive/html/qemu-devel/2019-02/msg06798.html
>
> Based-on: <20190225183757.27378-6-armbru@redhat.com>

I'll work this split into my v2.  Thanks!