[PATCH] viridian: Fix bank count counting

["Teddy Astie" <teddy.astie@xxxxxxxxxx>]

hv_vpset_nr_banks() incorrectly counts the number of bank by using hweight64()
instead of flsl(). This for instance problematic in case only the second bank
is selected (i.e >64 vCPUs, where here hweight64 gives 1), causing only the 
first
bank to be checked (non-valid) and the second (meaningful) one to be skipped.

Fixes: b4124682db6e ("viridian: add ExProcessorMasks variants of the flush 
hypercalls")
Signed-off-by: Teddy Astie <teddy.astie@xxxxxxxxxx>
---
 xen/arch/x86/hvm/viridian/viridian.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/x86/hvm/viridian/viridian.c 
b/xen/arch/x86/hvm/viridian/viridian.c
index 90e749ceb5..f5e526241d 100644
--- a/xen/arch/x86/hvm/viridian/viridian.c
+++ b/xen/arch/x86/hvm/viridian/viridian.c
@@ -601,7 +601,7 @@ static DEFINE_PER_CPU(union hypercall_vpset, 
hypercall_vpset);
 
 static unsigned int hv_vpset_nr_banks(struct hv_vpset *vpset)
 {
-    return hweight64(vpset->valid_bank_mask);
+    return fls64(vpset->valid_bank_mask);
 }
 
 static int hv_vpset_to_vpmask(const struct hv_vpset *in, paddr_t bank_gpa,
-- 
2.51.2



--
Teddy Astie | Vates XCP-ng Developer

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