[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <87r0onkyn4.ffs@tglx>
Date: Tue, 01 Aug 2023 09:30:39 +0200
From: Thomas Gleixner <tglx@...utronix.de>
To: Juergen Gross <jgross@...e.com>,
LKML <linux-kernel@...r.kernel.org>
Cc: x86@...nel.org, Andrew Cooper <andrew.cooper3@...rix.com>,
Tom Lendacky <thomas.lendacky@....com>,
Paolo Bonzini <pbonzini@...hat.com>,
Wei Liu <wei.liu@...nel.org>,
Arjan van de Ven <arjan@...ux.intel.com>,
Michael Kelley <mikelley@...rosoft.com>,
Peter Keresztes Schmidt <peter@...esztesschmidt.de>,
"Peter Zijlstra (Intel)" <peterz@...radead.org>
Subject: Re: [patch V2 50/58] x86/apic: Provide common init infrastructure
On Tue, Aug 01 2023 at 08:41, Thomas Gleixner wrote:
> On Mon, Jul 31 2023 at 17:48, Thomas Gleixner wrote:
>
>> On Mon, Jul 31 2023 at 15:10, Juergen Gross wrote:
>>> On 31.07.23 15:01, Thomas Gleixner wrote:
>>>>> apic_driver(xen_pv_apic);
>>>>
>>>> I wonder whether this explicit install is actually needed at all.
>>>> Shouldn't the driver be installed via the APIC probing mechanism
>>>> automagically?
>>>
>>> Only in case x86_init.irq.intr_mode_init is set appropriately. Today it is
>>> a nop for Xen PV, but that can be changed. I'll have a look.
>>
>> You could simply set that callback to default_setup_apic_routing() and
>> be done with it.
>
> Doesn't work because XEN overrides it already. So sure, lets just go
> with the solution you proposed. One more ugly or less in XEN/PV does not
> really matter much :)
>
> Let me grab this and put it into the right position in the queue.
Spoke too early. The below should work AFAICT from the code.
--- a/arch/x86/xen/apic.c
+++ b/arch/x86/xen/apic.c
@@ -99,10 +99,7 @@ static void xen_apic_icr_write(u32 low,
static int xen_apic_probe_pv(void)
{
- if (xen_pv_domain())
- return 1;
-
- return 0;
+ return xen_pv_domain();
}
static int xen_madt_oem_check(char *oem_id, char *oem_table_id)
@@ -157,20 +154,14 @@ static struct apic xen_pv_apic = {
.icr_read = xen_apic_icr_read,
.icr_write = xen_apic_icr_write,
};
-
-static void __init xen_apic_check(void)
-{
- apic_install_driver(&xen_pv_apic);
-}
+apic_driver(xen_pv_apic);
void __init xen_init_apic(void)
{
x86_apic_ops.io_apic_read = xen_io_apic_read;
- /* On PV guests the APIC CPUID bit is disabled so none of the
- * routines end up executing. */
- if (!xen_initial_domain())
- apic_install_driver(&xen_pv_apic);
-
- x86_platform.apic_post_init = xen_apic_check;
+ /*
+ * On PV guests the APIC CPUID bit is disabled so none of the
+ * routines end up executing.
+ */
+ apic_install_driver(&xen_pv_apic);
}
-apic_driver(xen_pv_apic);
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1325,7 +1325,7 @@ asmlinkage __visible void __init xen_sta
x86_platform.realmode_init = x86_init_noop;
x86_init.resources.memory_setup = xen_memory_setup;
- x86_init.irqs.intr_mode_select = x86_init_noop;
+ x86_init.irqs.intr_mode_select = xen_init_apic;
x86_init.irqs.intr_mode_init = x86_init_noop;
x86_init.oem.arch_setup = xen_arch_setup;
x86_init.oem.banner = xen_banner;
@@ -1366,13 +1366,6 @@ asmlinkage __visible void __init xen_sta
xen_init_capabilities();
-#ifdef CONFIG_X86_LOCAL_APIC
- /*
- * set up the basic apic ops.
- */
- xen_init_apic();
-#endif
-
machine_ops = xen_machine_ops;
/*
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -118,7 +118,11 @@ static inline void __init xen_init_vga(c
void xen_add_preferred_consoles(void);
+#ifdef CONFIG_X86_LOCAL_APIC
void __init xen_init_apic(void);
+#else
+# define xen_init_apic x86_init_noop
+#endif
#ifdef CONFIG_XEN_EFI
extern void xen_efi_init(struct boot_params *boot_params);
Powered by blists - more mailing lists