* [PATCH] x86/xenoprof: Fix kernel/user mode detection for HVM
@ 2012-10-12 16:11 Jacob Shin
2012-10-15 11:51 ` [PATCH, v2] x86/xenoprof: fix " Jan Beulich
0 siblings, 1 reply; 3+ messages in thread
From: Jacob Shin @ 2012-10-12 16:11 UTC (permalink / raw)
To: xen-devel
x86/xenoprof: Fix kernel/user mode detection for HVM
While trying oprofile under Xen, I noticed that HVM passive domain's kernel
addresses were showing up as user application. It turns out under HVM
get_cpu_user_regs()->cs contains 0x0000beef.
Signed-off-by: Jacob Shin <jacob.shin@amd.com>
diff -r e0e1350dfe9b xen/arch/x86/oprofile/xenoprof.c
--- a/xen/arch/x86/oprofile/xenoprof.c Thu Oct 11 15:57:00 2012 +0100
+++ b/xen/arch/x86/oprofile/xenoprof.c Fri Oct 12 10:48:37 2012 -0500
@@ -81,7 +81,11 @@ int xenoprofile_get_mode(const struct vc
return 2;
if ( is_hvm_vcpu(v) )
- return ((regs->cs & 3) != 3);
+ {
+ struct segment_register cs;
+ hvm_get_segment_register((struct vcpu *)v, x86_seg_cs, &cs);
+ return ((cs.sel & 3) != 3);
+ }
return guest_kernel_mode(v, regs);
}
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH, v2] x86/xenoprof: fix kernel/user mode detection for HVM
2012-10-12 16:11 [PATCH] x86/xenoprof: Fix kernel/user mode detection for HVM Jacob Shin
@ 2012-10-15 11:51 ` Jan Beulich
2012-10-15 12:09 ` Keir Fraser
0 siblings, 1 reply; 3+ messages in thread
From: Jan Beulich @ 2012-10-15 11:51 UTC (permalink / raw)
To: xen-devel; +Cc: Jacob Shin
[-- Attachment #1: Type: text/plain, Size: 1720 bytes --]
While trying oprofile under Xen, I noticed that HVM passive domain's
kernel addresses were showing up as user application. It turns out
under HVM get_cpu_user_regs()->cs contains 0x0000beef.
Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Don't cast away const-ness. Use SS instead of CS to determine ring.
Special-case real and protected mode.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
--- a/xen/arch/x86/oprofile/xenoprof.c
+++ b/xen/arch/x86/oprofile/xenoprof.c
@@ -74,16 +74,26 @@ int compat_oprof_arch_counter(XEN_GUEST_
return 0;
}
-int xenoprofile_get_mode(const struct vcpu *v,
- const struct cpu_user_regs *regs)
+int xenoprofile_get_mode(struct vcpu *curr, const struct cpu_user_regs *regs)
{
if ( !guest_mode(regs) )
return 2;
- if ( is_hvm_vcpu(v) )
- return ((regs->cs & 3) != 3);
+ if ( !is_hvm_vcpu(curr) )
+ return guest_kernel_mode(curr, regs);
- return guest_kernel_mode(v, regs);
+ switch ( hvm_guest_x86_mode(curr) )
+ {
+ struct segment_register ss;
+
+ case 0: /* real mode */
+ return 1;
+ case 1: /* vm86 mode */
+ return 0;
+ default:
+ hvm_get_segment_register(curr, x86_seg_ss, &ss);
+ return (ss.sel & 3) != 3;
+ }
}
/*
--- a/xen/include/asm-x86/xenoprof.h
+++ b/xen/include/asm-x86/xenoprof.h
@@ -51,7 +51,7 @@ struct cpu_user_regs;
void ibs_init(void);
extern u32 ibs_caps;
-int xenoprofile_get_mode(const struct vcpu *, const struct cpu_user_regs *);
+int xenoprofile_get_mode(struct vcpu *, const struct cpu_user_regs *);
static inline int xenoprof_backtrace_supported(void)
{
[-- Attachment #2: x86-oprof-hvm-mode.patch --]
[-- Type: text/plain, Size: 1770 bytes --]
x86/xenoprof: fix kernel/user mode detection for HVM
While trying oprofile under Xen, I noticed that HVM passive domain's
kernel addresses were showing up as user application. It turns out
under HVM get_cpu_user_regs()->cs contains 0x0000beef.
Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Don't cast away const-ness. Use SS instead of CS to determine ring.
Special-case real and protected mode.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
--- a/xen/arch/x86/oprofile/xenoprof.c
+++ b/xen/arch/x86/oprofile/xenoprof.c
@@ -74,16 +74,26 @@ int compat_oprof_arch_counter(XEN_GUEST_
return 0;
}
-int xenoprofile_get_mode(const struct vcpu *v,
- const struct cpu_user_regs *regs)
+int xenoprofile_get_mode(struct vcpu *curr, const struct cpu_user_regs *regs)
{
if ( !guest_mode(regs) )
return 2;
- if ( is_hvm_vcpu(v) )
- return ((regs->cs & 3) != 3);
+ if ( !is_hvm_vcpu(curr) )
+ return guest_kernel_mode(curr, regs);
- return guest_kernel_mode(v, regs);
+ switch ( hvm_guest_x86_mode(curr) )
+ {
+ struct segment_register ss;
+
+ case 0: /* real mode */
+ return 1;
+ case 1: /* vm86 mode */
+ return 0;
+ default:
+ hvm_get_segment_register(curr, x86_seg_ss, &ss);
+ return (ss.sel & 3) != 3;
+ }
}
/*
--- a/xen/include/asm-x86/xenoprof.h
+++ b/xen/include/asm-x86/xenoprof.h
@@ -51,7 +51,7 @@ struct cpu_user_regs;
void ibs_init(void);
extern u32 ibs_caps;
-int xenoprofile_get_mode(const struct vcpu *, const struct cpu_user_regs *);
+int xenoprofile_get_mode(struct vcpu *, const struct cpu_user_regs *);
static inline int xenoprof_backtrace_supported(void)
{
[-- Attachment #3: Type: text/plain, Size: 126 bytes --]
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Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH, v2] x86/xenoprof: fix kernel/user mode detection for HVM
2012-10-15 11:51 ` [PATCH, v2] x86/xenoprof: fix " Jan Beulich
@ 2012-10-15 12:09 ` Keir Fraser
0 siblings, 0 replies; 3+ messages in thread
From: Keir Fraser @ 2012-10-15 12:09 UTC (permalink / raw)
To: Jan Beulich, xen-devel; +Cc: Jacob Shin
On 15/10/2012 12:51, "Jan Beulich" <JBeulich@suse.com> wrote:
> While trying oprofile under Xen, I noticed that HVM passive domain's
> kernel addresses were showing up as user application. It turns out
> under HVM get_cpu_user_regs()->cs contains 0x0000beef.
>
> Signed-off-by: Jacob Shin <jacob.shin@amd.com>
>
> Don't cast away const-ness. Use SS instead of CS to determine ring.
> Special-case real and protected mode.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
> --- a/xen/arch/x86/oprofile/xenoprof.c
> +++ b/xen/arch/x86/oprofile/xenoprof.c
> @@ -74,16 +74,26 @@ int compat_oprof_arch_counter(XEN_GUEST_
> return 0;
> }
>
> -int xenoprofile_get_mode(const struct vcpu *v,
> - const struct cpu_user_regs *regs)
> +int xenoprofile_get_mode(struct vcpu *curr, const struct cpu_user_regs *regs)
> {
> if ( !guest_mode(regs) )
> return 2;
>
> - if ( is_hvm_vcpu(v) )
> - return ((regs->cs & 3) != 3);
> + if ( !is_hvm_vcpu(curr) )
> + return guest_kernel_mode(curr, regs);
>
> - return guest_kernel_mode(v, regs);
> + switch ( hvm_guest_x86_mode(curr) )
> + {
> + struct segment_register ss;
> +
> + case 0: /* real mode */
> + return 1;
> + case 1: /* vm86 mode */
> + return 0;
> + default:
> + hvm_get_segment_register(curr, x86_seg_ss, &ss);
> + return (ss.sel & 3) != 3;
> + }
> }
>
> /*
> --- a/xen/include/asm-x86/xenoprof.h
> +++ b/xen/include/asm-x86/xenoprof.h
> @@ -51,7 +51,7 @@ struct cpu_user_regs;
> void ibs_init(void);
> extern u32 ibs_caps;
>
> -int xenoprofile_get_mode(const struct vcpu *, const struct cpu_user_regs *);
> +int xenoprofile_get_mode(struct vcpu *, const struct cpu_user_regs *);
>
> static inline int xenoprof_backtrace_supported(void)
> {
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
^ permalink raw reply [flat|nested] 3+ messages in thread
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2012-10-12 16:11 [PATCH] x86/xenoprof: Fix kernel/user mode detection for HVM Jacob Shin
2012-10-15 11:51 ` [PATCH, v2] x86/xenoprof: fix " Jan Beulich
2012-10-15 12:09 ` Keir Fraser
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