* [PATCH] x86/xen/pvh: Enable PAE mode for 32-bit guest only when CONFIG_X86_PAE is set
@ 2023-10-20 9:08 Hou Wenlong
2023-10-20 15:39 ` Juergen Gross
0 siblings, 1 reply; 2+ messages in thread
From: Hou Wenlong @ 2023-10-20 9:08 UTC (permalink / raw)
To: linux-kernel
Cc: Hou Wenlong, Juergen Gross, Boris Ostrovsky, Darren Hart,
Andy Shevchenko, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, maintainer:X86 ARCHITECTURE 32-BIT AND 64-BIT,
H. Peter Anvin, moderated list:XEN HYPERVISOR X86,
open list:X86 PLATFORM DRIVERS - ARCH
The PVH entry is available for 32-bit KVM guests, and 32-bit KVM guests
do not depend on CONFIG_X86_PAE. However, mk_early_pgtbl_32() builds
different pagetables depending on whether CONFIG_X86_PAE is set.
Therefore, enabling PAE mode for 32-bit KVM guests without
CONFIG_X86_PAE being set would result in a boot failure during CR3
loading.
Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
---
arch/x86/platform/pvh/head.S | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/platform/pvh/head.S b/arch/x86/platform/pvh/head.S
index c4365a05ab83..085adb1b2313 100644
--- a/arch/x86/platform/pvh/head.S
+++ b/arch/x86/platform/pvh/head.S
@@ -70,10 +70,12 @@ SYM_CODE_START_LOCAL(pvh_start_xen)
mov $_pa(early_stack_end), %esp
+#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
/* Enable PAE mode. */
mov %cr4, %eax
orl $X86_CR4_PAE, %eax
mov %eax, %cr4
+#endif
#ifdef CONFIG_X86_64
/* Enable Long mode. */
--
2.31.1
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] x86/xen/pvh: Enable PAE mode for 32-bit guest only when CONFIG_X86_PAE is set
2023-10-20 9:08 [PATCH] x86/xen/pvh: Enable PAE mode for 32-bit guest only when CONFIG_X86_PAE is set Hou Wenlong
@ 2023-10-20 15:39 ` Juergen Gross
0 siblings, 0 replies; 2+ messages in thread
From: Juergen Gross @ 2023-10-20 15:39 UTC (permalink / raw)
To: Hou Wenlong, linux-kernel
Cc: Boris Ostrovsky, Darren Hart, Andy Shevchenko, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, Dave Hansen,
maintainer:X86 ARCHITECTURE 32-BIT AND 64-BIT, H. Peter Anvin,
moderated list:XEN HYPERVISOR X86,
open list:X86 PLATFORM DRIVERS - ARCH
[-- Attachment #1.1.1: Type: text/plain, Size: 525 bytes --]
On 20.10.23 11:08, Hou Wenlong wrote:
> The PVH entry is available for 32-bit KVM guests, and 32-bit KVM guests
> do not depend on CONFIG_X86_PAE. However, mk_early_pgtbl_32() builds
> different pagetables depending on whether CONFIG_X86_PAE is set.
> Therefore, enabling PAE mode for 32-bit KVM guests without
> CONFIG_X86_PAE being set would result in a boot failure during CR3
> loading.
>
> Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Juergen
[-- Attachment #1.1.2: OpenPGP public key --]
[-- Type: application/pgp-keys, Size: 3149 bytes --]
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 495 bytes --]
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2023-10-20 15:39 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-10-20 9:08 [PATCH] x86/xen/pvh: Enable PAE mode for 32-bit guest only when CONFIG_X86_PAE is set Hou Wenlong
2023-10-20 15:39 ` Juergen Gross
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®