On 04/02/2018 04:33 PM, Manish Jaggi wrote:
On 03/27/2018 03:48 PM, Marc Zyngier wrote:
On 27/03/18 10:07, Manish Jaggi wrote:
This patch is ported to xen from linux commit
b6f49035b4bf6e2709f2a5fed3107f5438c1fd02
KVM: arm64: vgic-v3: Add ICV_EOIR1_EL1 handler
Add a handler for writing the guest's view of the ICC_EOIR1_EL1
register. This involves dropping the priority of the interrupt,
and deactivating it if required (EOImode == 0).
Signed-off-by : Manish Jaggi <manish.ja...@cavium.com>
---
xen/arch/arm/arm64/vgic-v3-sr.c | 136
++++++++++++++++++++++++++++++++++++
xen/include/asm-arm/arm64/sysregs.h | 1 +
xen/include/asm-arm/gic_v3_defs.h | 4 ++
3 files changed, 141 insertions(+)
diff --git a/xen/arch/arm/arm64/vgic-v3-sr.c
b/xen/arch/arm/arm64/vgic-v3-sr.c
index 026d64506f..e32ec01f56 100644
--- a/xen/arch/arm/arm64/vgic-v3-sr.c
+++ b/xen/arch/arm/arm64/vgic-v3-sr.c
@@ -33,6 +33,7 @@
#define ICC_IAR1_EL1_SPURIOUS 0x3ff
#define VGIC_MAX_SPI 1019
+#define VGIC_MIN_LPI 8192
static int vgic_v3_bpr_min(void)
{
@@ -482,6 +483,137 @@ static void vreg_emulate_iar(struct
cpu_user_regs *regs, const union hsr hsr)
vgic_v3_read_iar(regs, hsr);
}
+static int vgic_v3_find_active_lr(int intid, uint64_t *lr_val)
+{
+ int i;
+ unsigned int used_lrs = gic_get_num_lrs();
This is quite a departure from the existing code. KVM always allocate
LRs sequentially, and used_lrs represents the current upper bound.
IIUC, Xen uses a function gic_find_unused_lr to find an unused LR.
xen/arch/arm/gic.c:
gic_raise_guest_irq
gic_find_unused_lr
Here,
you seem to be looking at *all* the LRs. Is that safe?
IIUC Xen does not maintain a used_lrs, it does have an lr_mask, but
that is static in gic.c
To do something like
+for_each_set_bit(i, lr_mask, nr_lrs)
+ {
+ u64 val = __gic_v3_get_lr(i);
+ u8 lr_prio = (val & ICH_LR_PRIORITY_MASK) >>
ICH_LR_PRIORITY_SHIFT;
+ /* Not pending in the state? */
+ if ((val & ICH_LR_STATE) != ICH_LR_PENDING_BIT)
+ continue;
I need to do some jugglery to make lr_mask visible outside of
xen/arch/arm/gic.c
The easiest would be to add an extern function, harder way would be to
add it in gic_hw_operations
- vgic_v3_highest_priority_lr iterates is interested in used LR's
which sre in Pending state.
- emulating IAR is done with interrupts disabled
- iterating over all the LRs and finding which ones are in Pending.
Just to add I was answering for using num_lrs for used_lrs, above was
for IAR flow.
This holds the same for EOIR flow as well.
The bigger point is unless I add some jugglery to access static value
outside gic.c
this is the only solution.
Stefano/Andre/Julien
Please suggest if there is some better way...
Are you
guaranteed not to have any stale state?
I would request Stefano/Andre/Julien to comment here...
In any case, the change should be documented.
+
+ for ( i = 0; i < used_lrs; i++ )
+ {
+ uint64_t val = gicv3_ich_read_lr(i);
+
+ if ( (val & ICH_LR_VIRTUAL_ID_MASK) == intid &&
+ (val & ICH_LR_ACTIVE_BIT) )
+ {
+ *lr_val = val;
+ return i;
+ }
+ }
+
+ *lr_val = ICC_IAR1_EL1_SPURIOUS;
+ return -1;
+}
Thanks,
M.
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