[Xen-devel] [PATCH v2] xen: setup pv irq ops vector earlier

[Juergen Gross <jgross@xxxxxxxx>]

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: <stable@xxxxxxxxxxxxxxx> # 4.14
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
 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


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