[PATCH v2] xen/apic: implement io apic read with hypercall

[PATCH v2] xen/apic: implement io apic read with hypercall

[Lin Ming]

Implements xen_io_apic_read with hypercall, so it returns proper
IO-APIC information instead of fabricated one.

Fallback to return an emulated IO_APIC values if hypercall fails.

Signed-off-by: Lin Ming <mlin@ss.pku.edu.cn>
---

v2: fallback to return an emulated IO_APIC values if hypercall fails

 arch/x86/xen/apic.c |   15 ++++++++++++++-
 1 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c
index aee16ab..1913bf2 100644
--- a/arch/x86/xen/apic.c
+++ b/arch/x86/xen/apic.c
@@ -1,14 +1,27 @@
 #include <linux/init.h>
 #include <asm/x86_init.h>
+#include <asm/apic.h>
+#include <xen/interface/physdev.h>
+#include <asm/xen/hypercall.h>
 
 unsigned int xen_io_apic_read(unsigned apic, unsigned reg)
 {
+	struct physdev_apic apic_op;
+	int ret;
+
+	apic_op.apic_physbase = mpc_ioapic_addr(apic);
+	apic_op.reg = reg;
+	ret = HYPERVISOR_physdev_op(PHYSDEVOP_apic_read, &apic_op);
+	if (!ret)
+		return apic_op.value;
+
+	/* fallback to return an emulated IO_APIC values */
 	if (reg == 0x1)
 		return 0x00170020;
 	else if (reg == 0x0)
 		return apic << 24;
 
-	return 0xff;
+	return 0xfd;
 }
 
 void __init xen_init_apic(void)
-- 
1.7.9

Re: [Xen-devel] [PATCH v2] xen/apic: implement io apic read with hypercall

[Konrad Rzeszutek Wilk]

On Tue, May 01, 2012 at 12:16:27AM +0800, Lin Ming wrote:
> Implements xen_io_apic_read with hypercall, so it returns proper
> IO-APIC information instead of fabricated one.

Looks good. I queued it up and sending the git pull to Ingo shortly.
> 
> Fallback to return an emulated IO_APIC values if hypercall fails.
> 
> Signed-off-by: Lin Ming <mlin@ss.pku.edu.cn>
> ---
> 
> v2: fallback to return an emulated IO_APIC values if hypercall fails
> 
>  arch/x86/xen/apic.c |   15 ++++++++++++++-
>  1 files changed, 14 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c
> index aee16ab..1913bf2 100644
> --- a/arch/x86/xen/apic.c
> +++ b/arch/x86/xen/apic.c
> @@ -1,14 +1,27 @@
>  #include <linux/init.h>
>  #include <asm/x86_init.h>
> +#include <asm/apic.h>
> +#include <xen/interface/physdev.h>
> +#include <asm/xen/hypercall.h>
>  
>  unsigned int xen_io_apic_read(unsigned apic, unsigned reg)
>  {
> +	struct physdev_apic apic_op;
> +	int ret;
> +
> +	apic_op.apic_physbase = mpc_ioapic_addr(apic);
> +	apic_op.reg = reg;
> +	ret = HYPERVISOR_physdev_op(PHYSDEVOP_apic_read, &apic_op);
> +	if (!ret)
> +		return apic_op.value;
> +
> +	/* fallback to return an emulated IO_APIC values */
>  	if (reg == 0x1)
>  		return 0x00170020;
>  	else if (reg == 0x0)
>  		return apic << 24;
>  
> -	return 0xff;
> +	return 0xfd;
>  }
>  
>  void __init xen_init_apic(void)
> -- 
> 1.7.9
> 
> 
> 
> 
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