On Mon, Aug 21, 2017 at 04:18:56PM +0100, Roger Pau Monné wrote:
> On Mon, Aug 21, 2017 at 09:14:45AM -0600, Jan Beulich wrote:
> > >>> On 21.08.17 at 16:49, <roger....@citrix.com> wrote:
> > > Another option is to (ab)use the msi.gflags field to add another flag
> > > in order to signal Xen whether the interrupt should be unmasked. This
> > > is in line with what you suggest below.
> >
> > From a brief look it looks like this would be doable, but the way these
> > flags are being communicated is rather ugly (the values used here
> > aren't part of the public interface, and hence it wasn't immediately
> > clear whether using one of the unused bits would be an option, but
> > it looks like it is).
>
> Yes, it's not pretty... Last used bit is 15, hence bit 16 could be
> used to signal to Xen whether the interrupt should be unmasked after
> binding. I have a half-drafted patch, will finish it now.
Hello,
Andreas, could you please give a try to the attached two patches? One
is for Xen and the other one is for QEMU.
Thanks, Roger.
diff --git a/xen/drivers/passthrough/io.c b/xen/drivers/passthrough/io.c
index ffeaf70be6..7e63007fbf 100644
--- a/xen/drivers/passthrough/io.c
+++ b/xen/drivers/passthrough/io.c
@@ -343,13 +343,16 @@ int pt_irq_create_bind(
uint8_t dest, dest_mode, delivery_mode;
int dest_vcpu_id;
const struct vcpu *vcpu;
+ uint32_t gflags = pt_irq_bind->u.msi.gflags & ~VMSI_UNMASKED;
+ struct irq_desc *desc;
+ unsigned long flags;
if ( !(pirq_dpci->flags & HVM_IRQ_DPCI_MAPPED) )
{
pirq_dpci->flags = HVM_IRQ_DPCI_MAPPED | HVM_IRQ_DPCI_MACH_MSI |
HVM_IRQ_DPCI_GUEST_MSI;
pirq_dpci->gmsi.gvec = pt_irq_bind->u.msi.gvec;
- pirq_dpci->gmsi.gflags = pt_irq_bind->u.msi.gflags;
+ pirq_dpci->gmsi.gflags = gflags;
/*
* 'pt_irq_create_bind' can be called after 'pt_irq_destroy_bind'.
* The 'pirq_cleanup_check' which would free the structure is only
@@ -402,13 +405,13 @@ int pt_irq_create_bind(
/* If pirq is already mapped as vmsi, update guest data/addr. */
if ( pirq_dpci->gmsi.gvec != pt_irq_bind->u.msi.gvec ||
- pirq_dpci->gmsi.gflags != pt_irq_bind->u.msi.gflags )
+ pirq_dpci->gmsi.gflags != gflags )
{
/* Directly clear pending EOIs before enabling new MSI info. */
pirq_guest_eoi(info);
pirq_dpci->gmsi.gvec = pt_irq_bind->u.msi.gvec;
- pirq_dpci->gmsi.gflags = pt_irq_bind->u.msi.gflags;
+ pirq_dpci->gmsi.gflags = gflags;
}
}
/* Calculate dest_vcpu_id for MSI-type pirq migration. */
@@ -439,6 +442,13 @@ int pt_irq_create_bind(
pi_update_irte(vcpu ? &vcpu->arch.hvm_vmx.pi_desc : NULL,
info, pirq_dpci->gmsi.gvec);
+ desc = irq_to_desc(info->arch.irq);
+ ASSERT(desc);
+
+ spin_lock_irqsave(&desc->lock, flags);
+ guest_mask_msi_irq(desc, !(pt_irq_bind->u.msi.gflags & VMSI_UNMASKED));
+ spin_unlock_irqrestore(&desc->lock, flags);
+
break;
}
diff --git a/xen/include/xen/hvm/irq.h b/xen/include/xen/hvm/irq.h
index 0d2c72c109..bdc843fb9a 100644
--- a/xen/include/xen/hvm/irq.h
+++ b/xen/include/xen/hvm/irq.h
@@ -56,6 +56,7 @@ struct dev_intx_gsi_link {
#define VMSI_DM_MASK 0x200
#define VMSI_DELIV_MASK 0x7000
#define VMSI_TRIG_MODE 0x8000
+#define VMSI_UNMASKED 0x10000
#define GFLAGS_SHIFT_RH 8
#define GFLAGS_SHIFT_DELIV_MODE 12
diff --git a/hw/xen/xen_pt_msi.c b/hw/xen/xen_pt_msi.c
index ff9a79f5d2..971441dbab 100644
--- a/hw/xen/xen_pt_msi.c
+++ b/hw/xen/xen_pt_msi.c
@@ -24,6 +24,7 @@
#define XEN_PT_GFLAGS_SHIFT_DM 9
#define XEN_PT_GFLAGSSHIFT_DELIV_MODE 12
#define XEN_PT_GFLAGSSHIFT_TRG_MODE 15
+#define XEN_PT_GFLAGSSHIFT_UNMASKED 16
#define latch(fld) latch[PCI_MSIX_ENTRY_##fld / sizeof(uint32_t)]
@@ -155,7 +156,8 @@ static int msi_msix_update(XenPCIPassthroughState *s,
int pirq,
bool is_msix,
int msix_entry,
- int *old_pirq)
+ int *old_pirq,
+ bool masked)
{
PCIDevice *d = &s->dev;
uint8_t gvec = msi_vector(data);
@@ -171,6 +173,8 @@ static int msi_msix_update(XenPCIPassthroughState *s,
table_addr = s->msix->mmio_base_addr;
}
+ gflags |= masked ? 0 : XEN_PT_GFLAGSSHIFT_UNMASKED;
+
rc = xc_domain_update_msi_irq(xen_xc, xen_domid, gvec,
pirq, gflags, table_addr);
@@ -274,7 +278,7 @@ int xen_pt_msi_update(XenPCIPassthroughState *s)
{
XenPTMSI *msi = s->msi;
return msi_msix_update(s, msi_addr64(msi), msi->data, msi->pirq,
- false, 0, &msi->pirq);
+ false, 0, &msi->pirq, false);
}
void xen_pt_msi_disable(XenPCIPassthroughState *s)
@@ -355,7 +359,8 @@ static int xen_pt_msix_update_one(XenPCIPassthroughState
*s, int entry_nr,
}
rc = msi_msix_update(s, entry->addr, entry->data, pirq, true,
- entry_nr, &entry->pirq);
+ entry_nr, &entry->pirq,
+ vec_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT);
if (!rc) {
entry->updated = false;
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