2018-07-12 15:41:55

by Jürgen Groß

[permalink] [raw]
Subject: [PATCH v2] xen: setup pv irq ops vector earlier

Setting pv_irq_ops for Xen PV domains should be done as early as
possible in order to support e.g. very early printk() usage.

The same applies to xen_vcpu_info_reset(0), as it is needed for the
pv irq ops.

Move the call of xen_setup_machphys_mapping() after initializing the
pv functions as it contains a WARN_ON(), too.

Remove the no longer necessary conditional in xen_init_irq_ops()
from PVH V1 times to make clear this is a PV only function.

Cc: <[email protected]> # 4.14
Signed-off-by: Juergen Gross <[email protected]>
---
arch/x86/xen/enlighten_pv.c | 24 +++++++++++-------------
arch/x86/xen/irq.c | 4 +---
2 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 4816b6f82a9a..439a94bf89ad 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1207,12 +1207,20 @@ asmlinkage __visible void __init xen_start_kernel(void)

xen_setup_features();

- xen_setup_machphys_mapping();
-
/* Install Xen paravirt ops */
pv_info = xen_info;
pv_init_ops.patch = paravirt_patch_default;
pv_cpu_ops = xen_cpu_ops;
+ xen_init_irq_ops();
+
+ /*
+ * Setup xen_vcpu early because it is needed for
+ * local_irq_disable(), irqs_disabled(), e.g. in printk().
+ *
+ * Don't do the full vcpu_info placement stuff until we have
+ * the cpu_possible_mask and a non-dummy shared_info.
+ */
+ xen_vcpu_info_reset(0);

x86_platform.get_nmi_reason = xen_get_nmi_reason;

@@ -1225,6 +1233,7 @@ asmlinkage __visible void __init xen_start_kernel(void)
* Set up some pagetable state before starting to set any ptes.
*/

+ xen_setup_machphys_mapping();
xen_init_mmu_ops();

/* Prevent unwanted bits from being set in PTEs. */
@@ -1250,20 +1259,9 @@ asmlinkage __visible void __init xen_start_kernel(void)
get_cpu_cap(&boot_cpu_data);
x86_configure_nx();

- xen_init_irq_ops();
-
/* Let's presume PV guests always boot on vCPU with id 0. */
per_cpu(xen_vcpu_id, 0) = 0;

- /*
- * Setup xen_vcpu early because idt_setup_early_handler needs it for
- * local_irq_disable(), irqs_disabled().
- *
- * Don't do the full vcpu_info placement stuff until we have
- * the cpu_possible_mask and a non-dummy shared_info.
- */
- xen_vcpu_info_reset(0);
-
idt_setup_early_handler();

xen_init_capabilities();
diff --git a/arch/x86/xen/irq.c b/arch/x86/xen/irq.c
index 74179852e46c..7515a19fd324 100644
--- a/arch/x86/xen/irq.c
+++ b/arch/x86/xen/irq.c
@@ -128,8 +128,6 @@ static const struct pv_irq_ops xen_irq_ops __initconst = {

void __init xen_init_irq_ops(void)
{
- /* For PVH we use default pv_irq_ops settings. */
- if (!xen_feature(XENFEAT_hvm_callback_vector))
- pv_irq_ops = xen_irq_ops;
+ pv_irq_ops = xen_irq_ops;
x86_init.irqs.intr_init = xen_init_IRQ;
}
--
2.13.7



2018-07-12 17:30:05

by Boris Ostrovsky

[permalink] [raw]
Subject: Re: [PATCH v2] xen: setup pv irq ops vector earlier

On 07/12/2018 11:40 AM, Juergen Gross wrote:
> Setting pv_irq_ops for Xen PV domains should be done as early as
> possible in order to support e.g. very early printk() usage.
>
> The same applies to xen_vcpu_info_reset(0), as it is needed for the
> pv irq ops.
>
> Move the call of xen_setup_machphys_mapping() after initializing the
> pv functions as it contains a WARN_ON(), too.
>
> Remove the no longer necessary conditional in xen_init_irq_ops()
> from PVH V1 times to make clear this is a PV only function.
>
> Cc: <[email protected]> # 4.14
> Signed-off-by: Juergen Gross <[email protected]>

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