Hi Marc,
On 2019/10/27 22:42, Marc Zyngier wrote:
The ITS VMAPP command gains some new fields with GICv4.1:
- a default doorbell, which allows a single doorbell to be used for
all the VLPIs routed to a given VPE
- a pointer to the configuration table (instead of having it in a register
that gets context switched)
- a flag indicating whether this is the first map or the last unmap for
this particulat VPE
- a flag indicating whether the pending table is known to be zeroed, or not
Plumb in the new fields in the VMAPP builder, and add the map/unmap
refcounting so that the ITS can do the right thing.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
[...]
@@ -605,19 +626,45 @@ static struct its_vpe *its_build_vmapp_cmd(struct its_node *its,
struct its_cmd_block *cmd,
struct its_cmd_desc *desc)
{
- unsigned long vpt_addr;
+ unsigned long vpt_addr, vconf_addr;
u64 target;
-
- vpt_addr = virt_to_phys(page_address(desc->its_vmapp_cmd.vpe->vpt_page));
- target = desc->its_vmapp_cmd.col->target_address + its->vlpi_redist_offset;
+ bool alloc;
its_encode_cmd(cmd, GITS_CMD_VMAPP);
its_encode_vpeid(cmd, desc->its_vmapp_cmd.vpe->vpe_id);
its_encode_valid(cmd, desc->its_vmapp_cmd.valid);
+
+ if (!desc->its_vmapp_cmd.valid) {
+ if (is_v4_1(its)) {
+ alloc = !atomic_dec_return(&desc->its_vmapp_cmd.vpe->vmapp_count);
+ its_encode_alloc(cmd, alloc);
+ }
+
+ goto out;
+ }
+
+ vpt_addr = virt_to_phys(page_address(desc->its_vmapp_cmd.vpe->vpt_page));
+ target = desc->its_vmapp_cmd.col->target_address + its->vlpi_redist_offset;
+
its_encode_target(cmd, target);
its_encode_vpt_addr(cmd, vpt_addr);
its_encode_vpt_size(cmd, LPI_NRBITS - 1);
+ if (!is_v4_1(its))
+ goto out;
+
+ vconf_addr = virt_to_phys(page_address(desc->its_vmapp_cmd.vpe->its_vm->vprop_page));
+
+ alloc = atomic_inc_and_test(&desc->its_vmapp_cmd.vpe->vmapp_count);
As the comment block on top of atomic_inc_and_test(atomic *v) says,
* Atomically increments @v by 1
* and returns true if the result is zero, or false for all
* other cases.
*/
We will always get the 'alloc' as false here, even if this is the
first mapping of this vPE. This is not as expected, I think.
And on the other hand, I wonder what is the reason for 'vmapp_count'
to be atomic_t?
Thanks,
Zenghui
+
+ its_encode_alloc(cmd, alloc);
+
+ /* We can only signal PTZ when alloc==1. Why do we have two bits? */
+ its_encode_ptz(cmd, alloc);
+ its_encode_vconf_addr(cmd, vconf_addr);
+ its_encode_vmapp_default_db(cmd, desc->its_vmapp_cmd.vpe->vpe_db_lpi);
+
+out:
its_fixup_cmd(cmd);
return valid_vpe(its, desc->its_vmapp_cmd.vpe);
@@ -3349,7 +3396,10 @@ static int its_vpe_init(struct its_vpe *vpe)
vpe->vpe_id = vpe_id;
vpe->vpt_page = vpt_page;
- vpe->vpe_proxy_event = -1;
+ if (gic_rdists->has_rvpeid)
+ atomic_set(&vpe->vmapp_count, 0);
+ else
+ vpe->vpe_proxy_event = -1;
return 0;
}
diff --git a/include/linux/irqchip/arm-gic-v4.h b/include/linux/irqchip/arm-gic-v4.h
index ab1396afe08a..6213ced6f199 100644
--- a/include/linux/irqchip/arm-gic-v4.h
+++ b/include/linux/irqchip/arm-gic-v4.h
@@ -37,8 +37,20 @@ struct its_vpe {
irq_hw_number_t vpe_db_lpi;
/* VPE resident */
bool resident;
- /* VPE proxy mapping */
- int vpe_proxy_event;
+ union {
+ /* GICv4.0 implementations */
+ struct {
+ /* VPE proxy mapping */
+ int vpe_proxy_event;
+ /* Implementation Defined Area Invalid */
+ bool idai;
+ };
+ /* GICv4.1 implementations */
+ struct {
+ atomic_t vmapp_count;
+ };
+ };
+
/*
* This collection ID is used to indirect the target
* redistributor for this VPE. The ID itself isn't involved in
@@ -47,8 +59,6 @@ struct its_vpe {
u16 col_idx;
/* Unique (system-wide) VPE identifier */
u16 vpe_id;
- /* Implementation Defined Area Invalid */
- bool idai;
/* Pending VLPIs on schedule out? */
bool pending_last;
};
_______________________________________________
kvmarm mailing list
kvmarm@xxxxxxxxxxxxxxxxxxxxx
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
