[Xen-devel] [PATCH v2 1/4] xen/domain: Introduce domain_max_vcpus() helper and implement per arch

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

This allows the common XEN_DOMCTL_max_vcpus handler to lose some x86-specific
architecture knowledge.

It turns out that Xen had the same magic number twice in-tree with different
names (HVM_MAX_VCPUS and MAX_HVM_VCPUS).  This removes all use of
MAX_HVM_VCPUS, and x86 uses HVM_MAX_VCPUS from the public headers.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
CC: Keir Fraser <keir@xxxxxxx>
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>
CC: Tim Deegan <tim@xxxxxxx>

---
v2: inline implementations in arch domain.h files

I would really have prefered to have the x86 implementation as a static inline
like the arm side, but because of the inclusion order, is_hvm_domain() is not
available in asm-x86/domain.h  I lack sufficient tuits to untangle this at the
moment.
---
 xen/common/domctl.c          |    3 +--
 xen/include/asm-arm/config.h |    1 -
 xen/include/asm-arm/domain.h |    5 +++++
 xen/include/asm-x86/config.h |    3 ---
 xen/include/asm-x86/domain.h |    3 +++
 5 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/xen/common/domctl.c b/xen/common/domctl.c
index ee578c0..33ecd45 100644
--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -608,8 +608,7 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) 
u_domctl)
 
         ret = -EINVAL;
         if ( (d == current->domain) || /* no domain_pause() */
-             (max > MAX_VIRT_CPUS) ||
-             (is_hvm_domain(d) && (max > MAX_HVM_VCPUS)) )
+             (max > domain_max_vcpus(d)) )
             break;
 
         /* Until Xenoprof can dynamically grow its vcpu-s array... */
diff --git a/xen/include/asm-arm/config.h b/xen/include/asm-arm/config.h
index 1b5a842..3b23e05 100644
--- a/xen/include/asm-arm/config.h
+++ b/xen/include/asm-arm/config.h
@@ -48,7 +48,6 @@
 #endif
 
 #define MAX_VIRT_CPUS 8
-#define MAX_HVM_VCPUS MAX_VIRT_CPUS
 
 #define asmlinkage /* Nothing needed */
 
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index 8b7dd85..9018c6a 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -249,6 +249,11 @@ struct arch_vcpu
 void vcpu_show_execution_state(struct vcpu *);
 void vcpu_show_registers(const struct vcpu *);
 
+static inline unsigned int domain_max_vcpus(const struct domain *d)
+{
+    return MAX_VIRT_CPUS;
+}
+
 #endif /* __ASM_DOMAIN_H__ */
 
 /*
diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h
index ad52d5b..2fbd68d 100644
--- a/xen/include/asm-x86/config.h
+++ b/xen/include/asm-x86/config.h
@@ -67,9 +67,6 @@
 #define NR_CPUS 256
 #endif
 
-/* Maximum we can support with current vLAPIC ID mapping. */
-#define MAX_HVM_VCPUS 128
-
 /* Linkage for x86 */
 #define __ALIGN .align 16,0x90
 #define __ALIGN_STR ".align 16,0x90"
diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
index 6a77a93..b233fbc 100644
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -9,6 +9,7 @@
 #include <asm/e820.h>
 #include <asm/mce.h>
 #include <public/vcpu.h>
+#include <public/hvm/hvm_info_table.h>
 
 #define has_32bit_shinfo(d)    ((d)->arch.has_32bit_shinfo)
 #define is_pv_32bit_domain(d)  ((d)->arch.is_32bit_pv)
@@ -527,6 +528,8 @@ void domain_cpuid(struct domain *d,
                   unsigned int  *ecx,
                   unsigned int  *edx);
 
+#define domain_max_vcpus(d) (is_hvm_domain(d) ? HVM_MAX_VCPUS : MAX_VIRT_CPUS)
+
 #endif /* __ASM_DOMAIN_H__ */
 
 /*
-- 
1.7.10.4


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