2023-06-15 13:05:49

by Juergen Gross

Subject: [PATCH] x86/xen: set default memory type for pv guests to WB

When running as an unprivileged PV-guest under Xen (not dom0), the
default MTRR memory type should be write-back.

Signed-off-by: Juergen Gross <[email protected]>
---
Based on tip x86/mtrr branch
---
arch/x86/xen/enlighten_pv.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 8732b85d5650..93b658248d01 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -187,6 +187,8 @@ static void __init xen_pv_init_platform(void)

if (xen_initial_domain())
xen_set_mtrr_data();
+ else
+ mtrr_overwrite_state(NULL, 0, MTRR_TYPE_WRBACK);
}

static void __init xen_pv_guest_late_init(void)
--
2.35.3

2023-06-15 19:54:09

by Boris Ostrovsky

Subject: Re: [PATCH] x86/xen: set default memory type for pv guests to WB

On 6/15/23 8:39 AM, Juergen Gross wrote:
> When running as an unprivileged PV-guest under Xen (not dom0), the
> default MTRR memory type should be write-back.
>
> Signed-off-by: Juergen Gross <[email protected]>

Reviewed-by: Boris Ostrovsky <[email protected]>

2023-06-16 09:36:13

by tip-bot2 for Dhananjay Ugwekar

Subject: [tip: x86/mtrr] x86/xen: Set default memory type for PV guests to WB

The following commit has been merged into the x86/mtrr branch of tip:

Commit-ID: 30d65d1b19850c9bc8c17dba8ebe9be5e0c17054
Gitweb: https://git.kernel.org/tip/30d65d1b19850c9bc8c17dba8ebe9be5e0c17054
Author: Juergen Gross <[email protected]>
AuthorDate: Thu, 15 Jun 2023 14:39:59 +02:00
Committer: Borislav Petkov (AMD) <[email protected]>
CommitterDate: Fri, 16 Jun 2023 11:22:33 +02:00

x86/xen: Set default memory type for PV guests to WB

When running as an unprivileged PV guest under Xen (not dom0), the
default MTRR memory type should be write-back.

Signed-off-by: Juergen Gross <[email protected]>
Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Reviewed-by: Boris Ostrovsky <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
arch/x86/xen/enlighten_pv.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 8732b85..93b6582 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -187,6 +187,8 @@ static void __init xen_pv_init_platform(void)

if (xen_initial_domain())
xen_set_mtrr_data();
+ else
+ mtrr_overwrite_state(NULL, 0, MTRR_TYPE_WRBACK);
}

static void __init xen_pv_guest_late_init(void)