diff mbox series

[v2,05/12] viridian: use hypercall_vpmask in hvcall_ipi()

Message ID 20201120094900.1489-6-paul@xen.org (mailing list archive)
State Superseded
Headers show
Series viridian: add support for ExProcessorMasks | expand

Commit Message

Paul Durrant Nov. 20, 2020, 9:48 a.m. UTC 
From: Paul Durrant <pdurrant@amazon.com>

A subsequent patch will need to IPI a mask of virtual processors potentially
wider than 64 bits. A previous patch introduced per-cpu hypercall_vpmask
to allow hvcall_flush() to deal with such wide masks. This patch modifies
the implementation of hvcall_ipi() to make use of the same mask structures,
introducing a for_each_vp() macro to facilitate traversing a mask.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
---
Cc: Wei Liu <wl@xen.org>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: "Roger Pau Monné" <roger.pau@citrix.com>

v2:
 - Drop the 'vp' loop now that vpmask_set() will do it internally
---
 xen/arch/x86/hvm/viridian/viridian.c | 43 +++++++++++++++++++++-------
 1 file changed, 32 insertions(+), 11 deletions(-)

Comments

Jan Beulich Nov. 20, 2020, 3:09 p.m. UTC | #1 
On 20.11.2020 10:48, Paul Durrant wrote:
> --- a/xen/arch/x86/hvm/viridian/viridian.c
> +++ b/xen/arch/x86/hvm/viridian/viridian.c
> @@ -551,6 +551,25 @@ static bool vpmask_test(const struct hypercall_vpmask *vpmask,
>      return test_bit(vp, vpmask->mask);
>  }
>  
> +static unsigned int vpmask_first(struct hypercall_vpmask *vpmask)

Now this and ...

> +{
> +    return find_first_bit(vpmask->mask, HVM_MAX_VCPUS);
> +}
> +
> +static unsigned int vpmask_next(struct hypercall_vpmask *vpmask, unsigned int vp)

... this should really have pointers to const as parameters.

> @@ -631,13 +650,21 @@ static int hvcall_flush(union hypercall_input *input,
>      return 0;
>  }
>  
> +static void send_ipi(struct hypercall_vpmask *vpmask, uint8_t vector)

And I guess this one should, too.

Jan
Durrant, Paul Nov. 20, 2020, 3:12 p.m. UTC | #2 
> -----Original Message-----
> From: Jan Beulich <jbeulich@suse.com>
> Sent: 20 November 2020 15:09
> To: Paul Durrant <paul@xen.org>
> Cc: Durrant, Paul <pdurrant@amazon.co.uk>; Wei Liu <wl@xen.org>; Andrew Cooper
> <andrew.cooper3@citrix.com>; Roger Pau Monné <roger.pau@citrix.com>; xen-devel@lists.xenproject.org
> Subject: RE: [EXTERNAL] [PATCH v2 05/12] viridian: use hypercall_vpmask in hvcall_ipi()
> 
> CAUTION: This email originated from outside of the organization. Do not click links or open
> attachments unless you can confirm the sender and know the content is safe.
> 
> 
> 
> On 20.11.2020 10:48, Paul Durrant wrote:
> > --- a/xen/arch/x86/hvm/viridian/viridian.c
> > +++ b/xen/arch/x86/hvm/viridian/viridian.c
> > @@ -551,6 +551,25 @@ static bool vpmask_test(const struct hypercall_vpmask *vpmask,
> >      return test_bit(vp, vpmask->mask);
> >  }
> >
> > +static unsigned int vpmask_first(struct hypercall_vpmask *vpmask)
> 
> Now this and ...
> 
> > +{
> > +    return find_first_bit(vpmask->mask, HVM_MAX_VCPUS);
> > +}
> > +
> > +static unsigned int vpmask_next(struct hypercall_vpmask *vpmask, unsigned int vp)
> 
> ... this should really have pointers to const as parameters.
> 
> > @@ -631,13 +650,21 @@ static int hvcall_flush(union hypercall_input *input,
> >      return 0;
> >  }
> >
> > +static void send_ipi(struct hypercall_vpmask *vpmask, uint8_t vector)
> 
> And I guess this one should, too.
> 

True, they can be const.

  Paul

> Jan
diff mbox series

Patch

diff --git a/xen/arch/x86/hvm/viridian/viridian.c b/xen/arch/x86/hvm/viridian/viridian.c
index 334d8527ff59..d8d8ecc89c80 100644
--- a/xen/arch/x86/hvm/viridian/viridian.c
+++ b/xen/arch/x86/hvm/viridian/viridian.c
@@ -551,6 +551,25 @@  static bool vpmask_test(const struct hypercall_vpmask *vpmask,
     return test_bit(vp, vpmask->mask);
 }
 
+static unsigned int vpmask_first(struct hypercall_vpmask *vpmask)
+{
+    return find_first_bit(vpmask->mask, HVM_MAX_VCPUS);
+}
+
+static unsigned int vpmask_next(struct hypercall_vpmask *vpmask, unsigned int vp)
+{
+    /*
+     * If vp + 1 > HVM_MAX_VCPUS then find_next_bit() will return
+     * HVM_MAX_VCPUS, ensuring the for_each_vp ( ... ) loop terminates.
+     */
+    return find_next_bit(vpmask->mask, HVM_MAX_VCPUS, vp + 1);
+}
+
+#define for_each_vp(vpmask, vp) \
+	for ( (vp) = vpmask_first(vpmask); \
+	      (vp) < HVM_MAX_VCPUS; \
+	      (vp) = vpmask_next(vpmask, vp) )
+
 /*
  * Windows should not issue the hypercalls requiring this callback in the
  * case where vcpu_id would exceed the size of the mask.
@@ -631,13 +650,21 @@  static int hvcall_flush(union hypercall_input *input,
     return 0;
 }
 
+static void send_ipi(struct hypercall_vpmask *vpmask, uint8_t vector)
+{
+    struct domain *currd = current->domain;
+    unsigned int vp;
+
+    for_each_vp ( vpmask, vp )
+        vlapic_set_irq(vcpu_vlapic(currd->vcpu[vp]), vector, 0);
+}
+
 static int hvcall_ipi(union hypercall_input *input,
                       union hypercall_output *output,
                       unsigned long input_params_gpa,
                       unsigned long output_params_gpa)
 {
-    struct domain *currd = current->domain;
-    struct vcpu *v;
+    struct hypercall_vpmask *vpmask = &this_cpu(hypercall_vpmask);
     uint32_t vector;
     uint64_t vcpu_mask;
 
@@ -676,16 +703,10 @@  static int hvcall_ipi(union hypercall_input *input,
     if ( vector < 0x10 || vector > 0xff )
         return -EINVAL;
 
-    for_each_vcpu ( currd, v )
-    {
-        if ( v->vcpu_id >= (sizeof(vcpu_mask) * 8) )
-            return -EINVAL;
+    vpmask_empty(vpmask);
+    vpmask_set(vpmask, 0, vcpu_mask);
 
-        if ( !(vcpu_mask & (1ul << v->vcpu_id)) )
-            continue;
-
-        vlapic_set_irq(vcpu_vlapic(v), vector, 0);
-    }
+    send_ipi(vpmask, vector);
 
     return 0;
 }