On 2019/9/30 17:20, Marc Zyngier wrote:
On 2019-09-28 03:02, Zenghui Yu wrote:
On 2019/9/24 2:25, Marc Zyngier wrote:
Just like for INVALL, GICv4.1 has grown a VPE-aware INVLPI register.
Let's plumb it in and make use of the DirectLPI code in that case.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
drivers/irqchip/irq-gic-v3-its.c | 19 +++++++++++++++++--
include/linux/irqchip/arm-gic-v3.h | 1 +
2 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v3-its.c
b/drivers/irqchip/irq-gic-v3-its.c
index b791c9beddf2..34595a7fcccb 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1200,13 +1200,27 @@ static void wait_for_syncr(void __iomem *rdbase)
static void direct_lpi_inv(struct irq_data *d)
{
+ struct its_vlpi_map *map = get_vlpi_map(d);
struct its_collection *col;
void __iomem *rdbase;
+ u64 val;
+
+ if (map) {
+ struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+
+ WARN_ON(!is_v4_1(its_dev->its));
+
+ val = GICR_INVLPIR_V;
+ val |= FIELD_PREP(GICR_INVLPIR_VPEID, map->vpe->vpe_id);
+ val |= FIELD_PREP(GICR_INVLPIR_INTID, map->vintid);
+ } else {
+ val = d->hwirq;
+ }
/* Target the redistributor this LPI is currently routed to */
col = irq_to_col(d);
I think irq_to_col() may not work when GICv4.1 VLPIs are involved in.
irq_to_col() gives us col_map[event] as the target redistributor,
but the correct one for VLPIs should be vlpi_maps[event]->vpe->col_idx.
These two are not always pointing to the same physical RD.
For example, if guest issues a MOVI against a VLPI, we will update the
corresponding vlpi_map->vpe and issue a VMOVI on ITS... but leave the
col_map[event] unchanged.
col_map[event] usually describes the physical LPI's CPU affinity, but
when this physical LPI serves as something which the VLPI is backed by,
we take really little care of it. Did I miss something here?
You didn't miss anything, and this is indeed another pretty bad bug.
The collection mapping is completely unused when the LPI becomes a
VLPI, and it is only the vpe->col_id that matters (which gets updated
on VMOVP).
This shows that irq_to_col() is the wrong abstraction, and what we're
interested is something that is more like 'irq to cpuid', allowing us
to directly point to the right distributor.
Please see the patch I just pushed[1], which does that.
Thanks,
M.
[1]
https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/commit/?h=irq/gic-v4.1-devel&id=aff363113eb26b6840136b69c2c7db2ea691db20
Yes, I think this makes sense.
Thanks,
zenghui
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