* [PATCH] optionrom/pvh: scan entire RSDP Area
@ 2020-03-03 10:52 Joe Richey
2020-03-04 8:55 ` Stefano Garzarella
0 siblings, 1 reply; 3+ messages in thread
From: Joe Richey @ 2020-03-03 10:52 UTC (permalink / raw)
To: qemu-trivial, qemu-devel, Stefano Garzarella, Liam Merwick,
Stefan Hajnoczi
Cc: Joe Richey
From: Joe Richey <joerichey@google.com>
Right now the PVH option rom scans for the RSDP from 0xE0000 to
0xE1FFF. This is probobly a typo, it should scan from 0xE0000 to
0xFFFFF.
This is actually an issue on some QEMU versions/machines. For example,
when I run QEMU the RSDP is placed at 0xf5ad0 which will not be picked
up by the current implementation.
This bug still allows a Linux guest to boot (in most configurations) as
the kernel will just scan for the RSDP if one isn't provided.
Signed-off-by: Joe Richey <joerichey@google.com>
---
pc-bios/optionrom/pvh_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/pc-bios/optionrom/pvh_main.c b/pc-bios/optionrom/pvh_main.c
index a015e1bf22..28e79d7fc4 100644
--- a/pc-bios/optionrom/pvh_main.c
+++ b/pc-bios/optionrom/pvh_main.c
@@ -29,7 +29,7 @@ asm (".code32"); /* this code will be executed in protected mode */
#define RSDP_SIGNATURE 0x2052545020445352LL /* "RSD PTR " */
#define RSDP_AREA_ADDR 0x000E0000
-#define RSDP_AREA_SIZE 2048
+#define RSDP_AREA_SIZE 0x00020000
#define EBDA_BASE_ADDR 0x0000040E
#define EBDA_SIZE 1024
--
2.25.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] optionrom/pvh: scan entire RSDP Area
2020-03-03 10:52 [PATCH] optionrom/pvh: scan entire RSDP Area Joe Richey
@ 2020-03-04 8:55 ` Stefano Garzarella
2020-03-04 12:20 ` Paolo Bonzini
0 siblings, 1 reply; 3+ messages in thread
From: Stefano Garzarella @ 2020-03-04 8:55 UTC (permalink / raw)
To: Joe Richey
Cc: qemu-trivial, Joe Richey, qemu-devel, Stefan Hajnoczi, Paolo Bonzini
CCing Paolo
On Tue, Mar 03, 2020 at 02:52:47AM -0800, Joe Richey wrote:
> From: Joe Richey <joerichey@google.com>
>
> Right now the PVH option rom scans for the RSDP from 0xE0000 to
> 0xE1FFF. This is probobly a typo, it should scan from 0xE0000 to
> 0xFFFFF.
>
> This is actually an issue on some QEMU versions/machines. For example,
> when I run QEMU the RSDP is placed at 0xf5ad0 which will not be picked
> up by the current implementation.
>
> This bug still allows a Linux guest to boot (in most configurations) as
> the kernel will just scan for the RSDP if one isn't provided.
>
> Signed-off-by: Joe Richey <joerichey@google.com>
> ---
> pc-bios/optionrom/pvh_main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/pc-bios/optionrom/pvh_main.c b/pc-bios/optionrom/pvh_main.c
> index a015e1bf22..28e79d7fc4 100644
> --- a/pc-bios/optionrom/pvh_main.c
> +++ b/pc-bios/optionrom/pvh_main.c
> @@ -29,7 +29,7 @@ asm (".code32"); /* this code will be executed in protected mode */
>
> #define RSDP_SIGNATURE 0x2052545020445352LL /* "RSD PTR " */
> #define RSDP_AREA_ADDR 0x000E0000
> -#define RSDP_AREA_SIZE 2048
> +#define RSDP_AREA_SIZE 0x00020000
> #define EBDA_BASE_ADDR 0x0000040E
> #define EBDA_SIZE 1024
>
The patch LGTM!
When I wrote this code I followed [1], where it is written that it can
be found in the "memory region from 0x000E0000 to 0x000FFFFF", so it
should be a typo.
Thanks for fixing it!
Fixes: 2785dc7b17 ("optionrom: add new PVH option rom")
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
[1] https://wiki.osdev.org/RSDP#Detecting_the_RSDP
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] optionrom/pvh: scan entire RSDP Area
2020-03-04 8:55 ` Stefano Garzarella
@ 2020-03-04 12:20 ` Paolo Bonzini
0 siblings, 0 replies; 3+ messages in thread
From: Paolo Bonzini @ 2020-03-04 12:20 UTC (permalink / raw)
To: Stefano Garzarella, Joe Richey
Cc: qemu-trivial, Joe Richey, qemu-devel, Stefan Hajnoczi
On 04/03/20 09:55, Stefano Garzarella wrote:
> CCing Paolo
>
> On Tue, Mar 03, 2020 at 02:52:47AM -0800, Joe Richey wrote:
>> From: Joe Richey <joerichey@google.com>
>>
>> Right now the PVH option rom scans for the RSDP from 0xE0000 to
>> 0xE1FFF. This is probobly a typo, it should scan from 0xE0000 to
>> 0xFFFFF.
>>
>> This is actually an issue on some QEMU versions/machines. For example,
>> when I run QEMU the RSDP is placed at 0xf5ad0 which will not be picked
>> up by the current implementation.
>>
>> This bug still allows a Linux guest to boot (in most configurations) as
>> the kernel will just scan for the RSDP if one isn't provided.
>>
>> Signed-off-by: Joe Richey <joerichey@google.com>
>> ---
>> pc-bios/optionrom/pvh_main.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/pc-bios/optionrom/pvh_main.c b/pc-bios/optionrom/pvh_main.c
>> index a015e1bf22..28e79d7fc4 100644
>> --- a/pc-bios/optionrom/pvh_main.c
>> +++ b/pc-bios/optionrom/pvh_main.c
>> @@ -29,7 +29,7 @@ asm (".code32"); /* this code will be executed in protected mode */
>>
>> #define RSDP_SIGNATURE 0x2052545020445352LL /* "RSD PTR " */
>> #define RSDP_AREA_ADDR 0x000E0000
>> -#define RSDP_AREA_SIZE 2048
>> +#define RSDP_AREA_SIZE 0x00020000
>> #define EBDA_BASE_ADDR 0x0000040E
>> #define EBDA_SIZE 1024
>>
>
> The patch LGTM!
>
> When I wrote this code I followed [1], where it is written that it can
> be found in the "memory region from 0x000E0000 to 0x000FFFFF", so it
> should be a typo.
>
> Thanks for fixing it!
>
>
> Fixes: 2785dc7b17 ("optionrom: add new PVH option rom")
> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
>
>
> [1] https://wiki.osdev.org/RSDP#Detecting_the_RSDP
>
Queued, thanks for both the fix and the Cc.
Paolo
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2020-03-04 12:21 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2020-03-03 10:52 [PATCH] optionrom/pvh: scan entire RSDP Area Joe Richey
2020-03-04 8:55 ` Stefano Garzarella
2020-03-04 12:20 ` Paolo Bonzini
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