[Xen-devel] [PATCH v6 5/7] x86/PVHv2: fix dom0_max_vcpus so it's capped to HVM_MAX_VCPUS for PVHv2 Dom0

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

PVHv2 Dom0 is limited to 128 vCPUs, as are all HVM guests at the moment. Fix
dom0_max_vcpus so it takes this limitation into account.

Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
Changes since v5:
 - Introduce a new limit local variable and use that to store the guest max
   number of vCPUs, this allows having a single check suitable for both PVH and
   PV.

Changes since v4:
 - Fix codding style to match rest of the function.

Changes since v3:
 - New in the series.
---
 xen/arch/x86/domain_build.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/xen/arch/x86/domain_build.c b/xen/arch/x86/domain_build.c
index 01c9348..407e479 100644
--- a/xen/arch/x86/domain_build.c
+++ b/xen/arch/x86/domain_build.c
@@ -40,6 +40,7 @@
 
 #include <public/version.h>
 #include <public/arch-x86/hvm/start_info.h>
+#include <public/hvm/hvm_info_table.h>
 
 static long __initdata dom0_nrpages;
 static long __initdata dom0_min_nrpages;
@@ -157,7 +158,7 @@ static nodemask_t __initdata dom0_nodes;
 
 unsigned int __init dom0_max_vcpus(void)
 {
-    unsigned int i, max_vcpus;
+    unsigned int i, max_vcpus, limit;
     nodeid_t node;
 
     for ( i = 0; i < dom0_nr_pxms; ++i )
@@ -177,8 +178,9 @@ unsigned int __init dom0_max_vcpus(void)
         max_vcpus = opt_dom0_max_vcpus_min;
     if ( opt_dom0_max_vcpus_max < max_vcpus )
         max_vcpus = opt_dom0_max_vcpus_max;
-    if ( max_vcpus > MAX_VIRT_CPUS )
-        max_vcpus = MAX_VIRT_CPUS;
+    limit = dom0_pvh ? HVM_MAX_VCPUS : MAX_VIRT_CPUS;
+    if ( max_vcpus > limit )
+        max_vcpus = limit;
 
     return max_vcpus;
 }
-- 
2.10.1 (Apple Git-78)


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