[xen master] xen/arm: Improve handling of nr_spis

[patchbot@xxxxxxx]

commit 6044c988c17f85fb874cc3372f0e3ab2ea1f925e
Author:     Michal Orzel <michal.orzel@xxxxxxx>
AuthorDate: Wed Mar 12 11:16:18 2025 +0100
Commit:     Michal Orzel <michal.orzel@xxxxxxx>
CommitDate: Thu Mar 13 08:10:48 2025 +0100

    xen/arm: Improve handling of nr_spis
    
    At the moment, we print a warning about max number of IRQs supported by
    GIC bigger than vGIC only for hardware domain. This check is not hwdom
    special, and should be made common. Also, in case of user not specifying
    nr_spis for dom0less domUs, we should take into account max number of
    IRQs supported by vGIC if it's smaller than for GIC.
    
    Introduce VGIC_MAX_IRQS macro and use it instead of hardcoded 992 value.
    Introduce VGIC_DEF_NR_SPIS macro to store the default number of vGIC SPIs.
    Fix calculation of nr_spis for dom0less domUs and make the GIC/vGIC max
    IRQs comparison common.
    
    Signed-off-by: Michal Orzel <michal.orzel@xxxxxxx>
    Reviewed-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>
---
 xen/arch/arm/dom0less-build.c   | 2 +-
 xen/arch/arm/domain_build.c     | 8 +-------
 xen/arch/arm/gic.c              | 3 +++
 xen/arch/arm/include/asm/vgic.h | 6 ++++++
 4 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/xen/arch/arm/dom0less-build.c b/xen/arch/arm/dom0less-build.c
index 31f31c38da..573b0d25ae 100644
--- a/xen/arch/arm/dom0less-build.c
+++ b/xen/arch/arm/dom0less-build.c
@@ -1018,7 +1018,7 @@ void __init create_domUs(void)
         {
             int vpl011_virq = GUEST_VPL011_SPI;
 
-            d_cfg.arch.nr_spis = gic_number_lines() - 32;
+            d_cfg.arch.nr_spis = VGIC_DEF_NR_SPIS;
 
             /*
              * The VPL011 virq is GUEST_VPL011_SPI, unless direct-map is
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 7cc141ef75..2b5b433183 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -2371,13 +2371,7 @@ void __init create_dom0(void)
 
     /* The vGIC for DOM0 is exactly emulating the hardware GIC */
     dom0_cfg.arch.gic_version = XEN_DOMCTL_CONFIG_GIC_NATIVE;
-    /*
-     * Xen vGIC supports a maximum of 992 interrupt lines.
-     * 32 are substracted to cover local IRQs.
-     */
-    dom0_cfg.arch.nr_spis = min(gic_number_lines(), (unsigned int) 992) - 32;
-    if ( gic_number_lines() > 992 )
-        printk(XENLOG_WARNING "Maximum number of vGIC IRQs exceeded.\n");
+    dom0_cfg.arch.nr_spis = VGIC_DEF_NR_SPIS;
     dom0_cfg.arch.tee_type = tee_get_type();
     dom0_cfg.max_vcpus = dom0_max_vcpus();
 
diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index acf61a4de3..e80fe0ca24 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -251,6 +251,9 @@ void __init gic_init(void)
         panic("Failed to initialize the GIC drivers\n");
     /* Clear LR mask for cpu0 */
     clear_cpu_lr_mask();
+
+    if ( gic_number_lines() > VGIC_MAX_IRQS )
+        printk(XENLOG_WARNING "Maximum number of vGIC IRQs exceeded\n");
 }
 
 void send_SGI_mask(const cpumask_t *cpumask, enum gic_sgi sgi)
diff --git a/xen/arch/arm/include/asm/vgic.h b/xen/arch/arm/include/asm/vgic.h
index e309dca1ad..35c0c6a8b0 100644
--- a/xen/arch/arm/include/asm/vgic.h
+++ b/xen/arch/arm/include/asm/vgic.h
@@ -329,6 +329,12 @@ extern void vgic_check_inflight_irqs_pending(struct vcpu 
*v,
  */
 #define vgic_num_irqs(d)        ((d)->arch.vgic.nr_spis + 32)
 
+/* Maximum number of IRQs supported by vGIC */
+#define VGIC_MAX_IRQS 992U
+
+/* Default number of vGIC SPIs. 32 are substracted to cover local IRQs. */
+#define VGIC_DEF_NR_SPIS (min(gic_number_lines(), VGIC_MAX_IRQS) - 32)
+
 /*
  * Allocate a guest VIRQ
  *  - spi == 0 => allocate a PPI. It will be the same on every vCPU
--
generated by git-patchbot for /home/xen/git/xen.git#master