On 07/06/2015 09:57 AM, Andrew Jones wrote:
On Sat, Jul 04, 2015 at 10:26:53AM +0200, Ingo Molnar wrote:
* Vitaly Kuznetsov <[email protected]> wrote:
Hypervisor callback interrupts are only accounted on Xen/Hyper-V and we
detect hypervisor's type in early boot. There is no point in having
always-zero HYP: line on other hypervisors or bare metal.
Suggested-by: Radim Krčmář <[email protected]>
Signed-off-by: Vitaly Kuznetsov <[email protected]>
---
arch/x86/kernel/irq.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 88b36648..0c82064 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -18,6 +18,7 @@
#include <asm/mce.h>
#include <asm/hw_irq.h>
#include <asm/desc.h>
+#include <asm/hypervisor.h>
#define CREATE_TRACE_POINTS
#include <asm/trace/irq_vectors.h>
@@ -139,10 +140,14 @@ int arch_show_interrupts(struct seq_file *p, int prec)
seq_puts(p, " Machine check polls\n");
#endif
#if IS_ENABLED(CONFIG_HYPERV) || defined(CONFIG_XEN)
- seq_printf(p, "%*s: ", prec, "HYP");
- for_each_online_cpu(j)
- seq_printf(p, "%10u ", irq_stats(j)->irq_hv_callback_count);
- seq_puts(p, " Hypervisor callback interrupts\n");
+ if (x86_hyper == &x86_hyper_ms_hyperv ||
+ x86_hyper == &x86_hyper_xen) {
+ seq_printf(p, "%*s: ", prec, "HYP");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ",
+ irq_stats(j)->irq_hv_callback_count);
+ seq_puts(p, " Hypervisor callback interrupts\n");
+ }
So I think we should simplify this to:
if (x86_hyper) {
...
}
this will print the HYP line on hypervisors that don't use
HYPERVISOR_CALLBACK_VECTOR, but it will make it a lot more self-maintaining, we
won't accidentally skip this line on hypervisors that start using the callback
IRQ.
This is a good point. When virt stuff creeps out, it's easy to lose track of
it. But, I would prefer that vmware and kvm guests don't have to have a
meaningless counter in /proc/interrupts. Also, for xen, I see that it only
matters for x86. ARM xen builds would also have a meaningless counter. Maybe
we should add a flags member to hypervisor_x86, and start using that in
these types of situations.
This is all x86 arch code so I don't see how it will make any difference
to Xen on ARM.
-boris
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