[kvm-unit-tests PATCH] ACPI: fix ACPI RSDP located before 0xF0000 is not found

[kvm-unit-tests PATCH] ACPI: fix ACPI RSDP located before 0xF0000 is not found

[Barzen, Benjamin]

From e107317d029b5298c88701b4bcc93bc64e28384b Mon Sep 17 00:00:00 2001
From: bbarzen <bbarzen@amazon.com>
Date: Wed, 29 Dec 2021 12:50:14 +0100
Subject: [PATCH] ACPI: fix ACPI RSDP located before 0xF0000 is not found

The function find_acpi_table_addr locates the ACPI RSDP by searching the
BIOS read only memory space. The official ACPI specification states that
this space goes from 0xE0000 to 0xFFFFF. The function currently starts
searching at 0xF0000. Any RSDP located before that address can
subsequently not be found.

Change the start address of the search to 0xE0000.

Singed-off-by: Benjamin Barzen <bbarzen@amazon.de>
---
 lib/x86/acpi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/x86/acpi.c b/lib/x86/acpi.c
index 4373106..bd7f022 100644
--- a/lib/x86/acpi.c
+++ b/lib/x86/acpi.c
@@ -19,7 +19,7 @@ void* find_acpi_table_addr(u32 sig)
         return (void*)(ulong)fadt->firmware_ctrl;
     }

-    for(addr = 0xf0000; addr < 0x100000; addr += 16) {
+    for(addr = 0xe0000; addr < 0x100000; addr += 16) {
        rsdp = (void*)addr;
        if (rsdp->signature == 0x2052545020445352LL)
           break;
-- 
2.32.0







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Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
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Ust-ID: DE 289 237 879

Re: [kvm-unit-tests PATCH] ACPI: fix ACPI RSDP located before 0xF0000 is not found

[Paolo Bonzini]

On 1/10/22 13:53, Barzen, Benjamin wrote:
>  From e107317d029b5298c88701b4bcc93bc64e28384b Mon Sep 17 00:00:00 2001
> From: bbarzen <bbarzen@amazon.com>
> Date: Wed, 29 Dec 2021 12:50:14 +0100
> Subject: [PATCH] ACPI: fix ACPI RSDP located before 0xF0000 is not found
> 
> The function find_acpi_table_addr locates the ACPI RSDP by searching the
> BIOS read only memory space. The official ACPI specification states that
> this space goes from 0xE0000 to 0xFFFFF. The function currently starts
> searching at 0xF0000. Any RSDP located before that address can
> subsequently not be found.
> 
> Change the start address of the search to 0xE0000.
> 
> Singed-off-by: Benjamin Barzen <bbarzen@amazon.de>
> ---
>   lib/x86/acpi.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/x86/acpi.c b/lib/x86/acpi.c
> index 4373106..bd7f022 100644
> --- a/lib/x86/acpi.c
> +++ b/lib/x86/acpi.c
> @@ -19,7 +19,7 @@ void* find_acpi_table_addr(u32 sig)
>           return (void*)(ulong)fadt->firmware_ctrl;
>       }
> 
> -    for(addr = 0xf0000; addr < 0x100000; addr += 16) {
> +    for(addr = 0xe0000; addr < 0x100000; addr += 16) {
>          rsdp = (void*)addr;
>          if (rsdp->signature == 0x2052545020445352LL)
>             break;

Queued, thanks.

Paolo