> -----邮件原件-----
> 发件人: linux-kernel-ow...@vger.kernel.org [mailto:linux-kernel-
> ow...@vger.kernel.org] 代表 Dou Liyang
> 发送时间: 2018年4月9日 16:47
> 收件人: Li,Rongqing <lirongq...@baidu.com>; linux-kernel@vger.kernel.org;
> t...@linutronix.de; mi...@redhat.com; h...@zytor.com; jgr...@suse.com;
> x...@kernel.org; pet...@infradead.org
> 主题: Re: 答复: [RFC PATCH] x86/acpi: Prevent x2apic id -1 from being
> accounted
>
> RongQing,
>
> At 04/09/2018 02:38 PM, Li,Rongqing wrote:
> >
> >
> >> -----邮件原件-----
> >> 发件人: Dou Liyang [mailto:douly.f...@cn.fujitsu.com]
> >> 发送时间: 2018年4月9日 13:38
> >> 收件人: Li,Rongqing <lirongq...@baidu.com>;
> >> linux-kernel@vger.kernel.org; t...@linutronix.de; mi...@redhat.com;
> >> h...@zytor.com; jgr...@suse.com; x...@kernel.org;
> pet...@infradead.org
> >> 主题: Re: [RFC PATCH] x86/acpi: Prevent x2apic id -1 from being
> >> accounted
> >>
> >> Hi RongQing,
> >>
> >> Is there an local x2apic whose ID is in your machine?
> >>
> >
> > I think no
>
> [...]
>
> > [ 0.000000] ACPI: X2APIC (apic_id[0xffffffff] uid[0x00] disabled)
> > [ 0.000000] ACPI: X2APIC (apic_id[0xffffffff] uid[0x01] disabled)
> > [ 0.000000] ACPI: X2APIC (apic_id[0xffffffff] uid[0x02] disabled)
>
> Ah, sure enough!
>
> [...]
> >
> >
> >> At 04/08/2018 07:38 PM, Li RongQing wrote:
> >>> local_apic_id of acpi_madt_local_x2apic is u32, it is converted to
> >>> int when checked by default_apic_id_valid() and return true if it is
> >>> larger than 0x7fffffff, this is wrong
> >>>
> >>
> >> For x2apic enabled systems,
> >>
> >> - the byte length of X2APIC ID is 4, and it can be larger than
> >> 0x7fffffff in theory
> >>
> >
> > Yes
> >
> >> - the ->apic_id_valid points to x2apic_apic_id_valid(), which always
> >> return _ture_ , not default_apic_id_valid().
> >>
> >
> > To this machine, the apic is apic_flat
>
> I see, I am sorry the title and changelog make me misunderstand.
>
> Here, actually, we prevent all the X2APIC Id from being parsed in
> non-x2apic mode, not just 0xFFFFFFFF. because the values of x2APIC ID
> must be 255 and greater in ACPI MADT.
>
Thanks. How about the below modification:
commit 96ba42cf87ce0e62d500004c01bfa9a9479b2e87
Author: Li RongQing <lirongq...@baidu.com>
Date: Sun Apr 8 18:54:10 2018 +0800
x86/acpi: Prevent all the X2APIC Id from being parsed in non-x2apic mode
the values of x2APIC ID is greater than 0xff in ACPI MADT, if acpi
is apic_flat, default_apic_id_valid() is called to check id which
is converted from u32 to int, will return true if id is larger than
0x7fffffff, this is wrong
and if local_apic_id is invalid, we should prevent it from being
accounted
This fixes a bug that Purley platform displays too many possible cpu
Signed-off-by: Li RongQing <lirongq...@baidu.com>
Suggested-by:: Dou Liyang <douly.f...@cn.fujitsu.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Thomas Gleixner <t...@linutronix.de>
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 40a3d3642f3a..08acd954f00e 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -313,7 +313,7 @@ struct apic {
/* Probe, setup and smpboot functions */
int (*probe)(void);
int (*acpi_madt_oem_check)(char *oem_id, char *oem_table_id);
- int (*apic_id_valid)(int apicid);
+ int (*apic_id_valid)(u32 apicid);
int (*apic_id_registered)(void);
bool (*check_apicid_used)(physid_mask_t *map, int apicid);
@@ -486,7 +486,7 @@ static inline unsigned int read_apic_id(void)
return apic->get_apic_id(reg);
}
-extern int default_apic_id_valid(int apicid);
+extern int default_apic_id_valid(u32 apicid);
extern int default_acpi_madt_oem_check(char *, char *);
extern void default_setup_apic_routing(void);
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 7a37d9357bc4..4ba949de1ca9 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -200,7 +200,7 @@ acpi_parse_x2apic(struct acpi_subtable_header *header,
const unsigned long end)
{
struct acpi_madt_local_x2apic *processor = NULL;
#ifdef CONFIG_X86_X2APIC
- int apic_id;
+ u32 apic_id;
u8 enabled;
#endif
@@ -222,10 +222,13 @@ acpi_parse_x2apic(struct acpi_subtable_header *header,
const unsigned long end)
* to not preallocating memory for all NR_CPUS
* when we use CPU hotplug.
*/
- if (!apic->apic_id_valid(apic_id) && enabled)
- printk(KERN_WARNING PREFIX "x2apic entry ignored\n");
- else
- acpi_register_lapic(apic_id, processor->uid, enabled);
+ if (!apic->apic_id_valid(apic_id)) {
+ if (enabled)
+ printk(KERN_WARNING PREFIX "x2apic entry ignored\n");
+ return 0;
+ }
+
+ acpi_register_lapic(apic_id, processor->uid, enabled);
#else
printk(KERN_WARNING PREFIX "x2apic entry ignored\n");
#endif
diff --git a/arch/x86/kernel/apic/apic_common.c
b/arch/x86/kernel/apic/apic_common.c
index a360801779ae..02b4839478b1 100644
--- a/arch/x86/kernel/apic/apic_common.c
+++ b/arch/x86/kernel/apic/apic_common.c
@@ -40,7 +40,7 @@ int default_check_phys_apicid_present(int phys_apicid)
return physid_isset(phys_apicid, phys_cpu_present_map);
}
-int default_apic_id_valid(int apicid)
+int default_apic_id_valid(u32 apicid)
{
return (apicid < 255);
}
diff --git a/arch/x86/kernel/apic/apic_numachip.c
b/arch/x86/kernel/apic/apic_numachip.c
index 134e04506ab4..78778b54f904 100644
--- a/arch/x86/kernel/apic/apic_numachip.c
+++ b/arch/x86/kernel/apic/apic_numachip.c
@@ -56,7 +56,7 @@ static u32 numachip2_set_apic_id(unsigned int id)
return id << 24;
}
-static int numachip_apic_id_valid(int apicid)
+static int numachip_apic_id_valid(u32 apicid)
{
/* Trust what bootloader passes in MADT */
return 1;
diff --git a/arch/x86/kernel/apic/x2apic.h b/arch/x86/kernel/apic/x2apic.h
index b107de381cb5..a49b3604027f 100644
--- a/arch/x86/kernel/apic/x2apic.h
+++ b/arch/x86/kernel/apic/x2apic.h
@@ -1,6 +1,6 @@
/* Common bits for X2APIC cluster/physical modes. */
-int x2apic_apic_id_valid(int apicid);
+int x2apic_apic_id_valid(u32 apicid);
int x2apic_apic_id_registered(void);
void __x2apic_send_IPI_dest(unsigned int apicid, int vector, unsigned int
dest);
unsigned int x2apic_get_apic_id(unsigned long id);
diff --git a/arch/x86/kernel/apic/x2apic_phys.c
b/arch/x86/kernel/apic/x2apic_phys.c
index e2829bf40e4a..b5cf9e7b3830 100644
--- a/arch/x86/kernel/apic/x2apic_phys.c
+++ b/arch/x86/kernel/apic/x2apic_phys.c
@@ -101,7 +101,7 @@ static int x2apic_phys_probe(void)
}
/* Common x2apic functions, also used by x2apic_cluster */
-int x2apic_apic_id_valid(int apicid)
+int x2apic_apic_id_valid(u32 apicid)
{
return 1;
}
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c
b/arch/x86/kernel/apic/x2apic_uv_x.c
index f11910b44638..efaf2d4f9c3c 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -557,7 +557,7 @@ static void uv_send_IPI_all(int vector)
uv_send_IPI_mask(cpu_online_mask, vector);
}
-static int uv_apic_id_valid(int apicid)
+static int uv_apic_id_valid(u32 apicid)
{
return 1;
}
diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c
index 2163888497d3..5e53bfbe5823 100644
--- a/arch/x86/xen/apic.c
+++ b/arch/x86/xen/apic.c
@@ -112,7 +112,7 @@ static int xen_madt_oem_check(char *oem_id, char
*oem_table_id)
return xen_pv_domain();
}
-static int xen_id_always_valid(int apicid)
+static int xen_id_always_valid(u32 apicid)
{
return 1;
}
