* [PATCH] Use EfiACPIReclaimMemory for ESRT
@ 2022-09-30 21:02 Demi Marie Obenour
2022-10-03 10:01 ` Roger Pau Monné
2022-10-04 8:31 ` Jan Beulich
0 siblings, 2 replies; 4+ messages in thread
From: Demi Marie Obenour @ 2022-09-30 21:02 UTC (permalink / raw)
To: xen-devel
Cc: Demi Marie Obenour, Jan Beulich, Marek Marczykowski-Górecki
As discussed on xen-devel, using EfiRuntimeServicesData for more than is
absolutely necessary is a bad idea.
---
xen/common/efi/boot.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)
diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
index db0340c8e2628314226c618dda11ede4c62fdf3b..dba23439758d1e842d267dcd19448e0f9113b115 100644
--- a/xen/common/efi/boot.c
+++ b/xen/common/efi/boot.c
@@ -601,11 +601,13 @@ static size_t __init get_esrt_size(const EFI_MEMORY_DESCRIPTOR *desc)
if ( physical_start > esrt || esrt - physical_start >= len )
return 0;
/*
- * The specification requires EfiBootServicesData, but accept
- * EfiRuntimeServicesData, which is a more logical choice.
+ * The specification requires EfiBootServicesData, but also accept
+ * EfiRuntimeServicesData (for compatibility) and EfiACPIReclaimMemory
+ * (which will contain the tables after successful kexec).
*/
if ( (desc->Type != EfiRuntimeServicesData) &&
- (desc->Type != EfiBootServicesData) )
+ (desc->Type != EfiBootServicesData) &&
+ (desc->Type != EfiACPIReclaimMemory) )
return 0;
available_len = len - (esrt - physical_start);
if ( available_len <= offsetof(EFI_SYSTEM_RESOURCE_TABLE, Entries) )
@@ -1144,18 +1146,19 @@ static void __init efi_relocate_esrt(EFI_SYSTEM_TABLE *SystemTable)
for ( i = 0; i < info_size; i += mdesc_size )
{
/*
- * ESRT needs to be moved to memory of type EfiRuntimeServicesData
+ * ESRT needs to be moved to memory of type EfiACPIReclaimMemory
* so that the memory it is in will not be used for other purposes.
*/
void *new_esrt = NULL;
- size_t esrt_size = get_esrt_size(memory_map + i);
+ const EFI_MEMORY_DESCRIPTOR *desc = memory_map + i;
+ size_t esrt_size = get_esrt_size(desc);
if ( !esrt_size )
continue;
- if ( ((EFI_MEMORY_DESCRIPTOR *)(memory_map + i))->Type ==
- EfiRuntimeServicesData )
+ if ( desc->Type == EfiRuntimeServicesData ||
+ desc->Type == EfiACPIReclaimMemory )
break; /* ESRT already safe from reuse */
- status = efi_bs->AllocatePool(EfiRuntimeServicesData, esrt_size,
+ status = efi_bs->AllocatePool(EfiACPIReclaimMemory, esrt_size,
&new_esrt);
if ( status == EFI_SUCCESS && new_esrt )
{
--
Sincerely,
Demi Marie Obenour (she/her/hers)
Invisible Things Lab
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] Use EfiACPIReclaimMemory for ESRT
2022-09-30 21:02 [PATCH] Use EfiACPIReclaimMemory for ESRT Demi Marie Obenour
@ 2022-10-03 10:01 ` Roger Pau Monné
2022-10-04 8:31 ` Jan Beulich
1 sibling, 0 replies; 4+ messages in thread
From: Roger Pau Monné @ 2022-10-03 10:01 UTC (permalink / raw)
To: Demi Marie Obenour
Cc: xen-devel, Jan Beulich, Marek Marczykowski-Górecki
On Fri, Sep 30, 2022 at 05:02:02PM -0400, Demi Marie Obenour wrote:
> As discussed on xen-devel, using EfiRuntimeServicesData for more than is
> absolutely necessary is a bad idea.
I'm afraid this needs a proper commit message: commit messages need to
be able to stand alone on it's own in most cases, without references
to external sources. IMO I would add a summary of the thread that
happened on xen-devel: scenario, issue and how it's fixed, and also
provide a link (from lists.xenproject.org) to the conversation thread.
It's also missing a SoB.
Thanks, Roger.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Use EfiACPIReclaimMemory for ESRT
2022-09-30 21:02 [PATCH] Use EfiACPIReclaimMemory for ESRT Demi Marie Obenour
2022-10-03 10:01 ` Roger Pau Monné
@ 2022-10-04 8:31 ` Jan Beulich
2022-10-04 14:59 ` Demi Marie Obenour
1 sibling, 1 reply; 4+ messages in thread
From: Jan Beulich @ 2022-10-04 8:31 UTC (permalink / raw)
To: Demi Marie Obenour; +Cc: Marek Marczykowski-Górecki, xen-devel
On 30.09.2022 23:02, Demi Marie Obenour wrote:
> As discussed on xen-devel, using EfiRuntimeServicesData for more than is
> absolutely necessary is a bad idea.
> ---
> xen/common/efi/boot.c | 19 +++++++++++--------
> 1 file changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
> index db0340c8e2628314226c618dda11ede4c62fdf3b..dba23439758d1e842d267dcd19448e0f9113b115 100644
> --- a/xen/common/efi/boot.c
> +++ b/xen/common/efi/boot.c
> @@ -601,11 +601,13 @@ static size_t __init get_esrt_size(const EFI_MEMORY_DESCRIPTOR *desc)
> if ( physical_start > esrt || esrt - physical_start >= len )
> return 0;
> /*
> - * The specification requires EfiBootServicesData, but accept
> - * EfiRuntimeServicesData, which is a more logical choice.
> + * The specification requires EfiBootServicesData, but also accept
> + * EfiRuntimeServicesData (for compatibility) and EfiACPIReclaimMemory
> + * (which will contain the tables after successful kexec).
What's the compatibility concern here? We haven't released any Xen
version yet where the table would be moved to EfiRuntimeServicesData.
Jan
> */
> if ( (desc->Type != EfiRuntimeServicesData) &&
> - (desc->Type != EfiBootServicesData) )
> + (desc->Type != EfiBootServicesData) &&
> + (desc->Type != EfiACPIReclaimMemory) )
> return 0;
> available_len = len - (esrt - physical_start);
> if ( available_len <= offsetof(EFI_SYSTEM_RESOURCE_TABLE, Entries) )
> @@ -1144,18 +1146,19 @@ static void __init efi_relocate_esrt(EFI_SYSTEM_TABLE *SystemTable)
> for ( i = 0; i < info_size; i += mdesc_size )
> {
> /*
> - * ESRT needs to be moved to memory of type EfiRuntimeServicesData
> + * ESRT needs to be moved to memory of type EfiACPIReclaimMemory
> * so that the memory it is in will not be used for other purposes.
> */
> void *new_esrt = NULL;
> - size_t esrt_size = get_esrt_size(memory_map + i);
> + const EFI_MEMORY_DESCRIPTOR *desc = memory_map + i;
> + size_t esrt_size = get_esrt_size(desc);
>
> if ( !esrt_size )
> continue;
> - if ( ((EFI_MEMORY_DESCRIPTOR *)(memory_map + i))->Type ==
> - EfiRuntimeServicesData )
> + if ( desc->Type == EfiRuntimeServicesData ||
> + desc->Type == EfiACPIReclaimMemory )
> break; /* ESRT already safe from reuse */
> - status = efi_bs->AllocatePool(EfiRuntimeServicesData, esrt_size,
> + status = efi_bs->AllocatePool(EfiACPIReclaimMemory, esrt_size,
> &new_esrt);
> if ( status == EFI_SUCCESS && new_esrt )
> {
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Use EfiACPIReclaimMemory for ESRT
2022-10-04 8:31 ` Jan Beulich
@ 2022-10-04 14:59 ` Demi Marie Obenour
0 siblings, 0 replies; 4+ messages in thread
From: Demi Marie Obenour @ 2022-10-04 14:59 UTC (permalink / raw)
To: Jan Beulich; +Cc: Marek Marczykowski-Górecki, xen-devel
[-- Attachment #1: Type: text/plain, Size: 1402 bytes --]
On Tue, Oct 04, 2022 at 10:31:25AM +0200, Jan Beulich wrote:
> On 30.09.2022 23:02, Demi Marie Obenour wrote:
> > As discussed on xen-devel, using EfiRuntimeServicesData for more than is
> > absolutely necessary is a bad idea.
> > ---
> > xen/common/efi/boot.c | 19 +++++++++++--------
> > 1 file changed, 11 insertions(+), 8 deletions(-)
> >
> > diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
> > index db0340c8e2628314226c618dda11ede4c62fdf3b..dba23439758d1e842d267dcd19448e0f9113b115 100644
> > --- a/xen/common/efi/boot.c
> > +++ b/xen/common/efi/boot.c
> > @@ -601,11 +601,13 @@ static size_t __init get_esrt_size(const EFI_MEMORY_DESCRIPTOR *desc)
> > if ( physical_start > esrt || esrt - physical_start >= len )
> > return 0;
> > /*
> > - * The specification requires EfiBootServicesData, but accept
> > - * EfiRuntimeServicesData, which is a more logical choice.
> > + * The specification requires EfiBootServicesData, but also accept
> > + * EfiRuntimeServicesData (for compatibility) and EfiACPIReclaimMemory
> > + * (which will contain the tables after successful kexec).
>
> What's the compatibility concern here? We haven't released any Xen
> version yet where the table would be moved to EfiRuntimeServicesData.
Old buggy firmware.
--
Sincerely,
Demi Marie Obenour (she/her/hers)
Invisible Things Lab
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^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2022-10-04 15:00 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2022-09-30 21:02 [PATCH] Use EfiACPIReclaimMemory for ESRT Demi Marie Obenour
2022-10-03 10:01 ` Roger Pau Monné
2022-10-04 8:31 ` Jan Beulich
2022-10-04 14:59 ` Demi Marie Obenour
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