On 27.08.25 13:25, Leonid Komarianskyi wrote:
Hello Leonid
Hello Volodymyr,
Thank you for your suggestion.
On 27.08.25 02:08, Volodymyr Babchuk wrote:
Hi Leonid,
Leonid Komarianskyi <leonid_komarians...@epam.com> writes:
The Dom0 and DomUs logic for the dom0less configuration in create_dom0()
and arch_create_domUs() has been updated to account for extended SPIs
when supported by the hardware and enabled with CONFIG_GICV3_ESPI. These
changes ensure the proper calculation of the maximum number of SPIs and
eSPIs available to Dom0 and DomUs in dom0less setups.
When eSPIs are supported by the hardware and CONFIG_GICV3_ESPI is
enabled, the maximum number of eSPI interrupts is calculated using the
ESPI_BASE_INTID offset (4096) and is limited to 1024, with 32 IRQs
subtracted. To ensure compatibility with DomUs (Dom0 setups) domains,
where this adjustment is applied by the toolstack during domain
creation, while for Dom0 or DomUs in Dom0, it is handled directly during
VGIC initialization. If eSPIs are not supported, the calculation
defaults to using the standard SPI range, with a maximum value of
960 interrupt lines, as it works currently.
Signed-off-by: Leonid Komarianskyi <leonid_komarians...@epam.com>
---
Changes in V2:
- no changes
Changes in V3:
- renamed macro VGIC_DEF_NR_ESPIS to more appropriate VGIC_DEF_MAX_SPI
Will VGIC_DEF_MAX_ESPI be better? When other code refer to "SPI" it mean
"common SPI" (less than 1022), while ESPI is used for extended SPI. So,
naturally it feels that VGIC_DEF_MAX_SPI should be equal to 1022...
Yes, I agree with that - VGIC_DEF_MAX_ESPI sounds more appropriate in
this case. I will rename it in V4.
- added eSPI initialization for dom0less setups
- fixed comment with mentions about dom0less builds
- fixed formatting for lines with more than 80 symbols
- updated commit message
---
xen/arch/arm/dom0less-build.c | 12 ++++++++++++
xen/arch/arm/domain_build.c | 11 +++++++++++
xen/arch/arm/include/asm/vgic.h | 14 ++++++++++++++
3 files changed, 37 insertions(+)
diff --git a/xen/arch/arm/dom0less-build.c b/xen/arch/arm/dom0less-build.c
index 69b9ea22ce..f4f9077db5 100644
--- a/xen/arch/arm/dom0less-build.c
+++ b/xen/arch/arm/dom0less-build.c
@@ -286,6 +286,18 @@ void __init arch_create_domUs(struct dt_device_node *node,
int vpl011_virq = GUEST_VPL011_SPI;
d_cfg->arch.nr_spis = VGIC_DEF_NR_SPIS;
+#ifdef CONFIG_GICV3_ESPI
+ /*
+ * Check if the hardware supports extended SPIs (even if the
+ * appropriate config is set). If not, the common SPI range
+ * will be used. Otherwise overwrite the nr_spis with the maximum
+ * available INTID from eSPI range. In that case, the number of
+ * regular SPIs will be adjusted to the maximum value during vGIC
+ * initialization.
+ */
+ if ( gic_number_espis() > 0 )
+ d_cfg->arch.nr_spis = VGIC_DEF_MAX_SPI;
+#endif
/*
* 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 d91a71acfd..148a8bdb60 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -2055,6 +2055,17 @@ 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;
dom0_cfg.arch.nr_spis = VGIC_DEF_NR_SPIS;
+#ifdef CONFIG_GICV3_ESPI
+ /*
+ * Check if the hardware supports extended SPIs (even if the appropriate
+ * config is set). If not, the common SPI range will be used. Otherwise
+ * overwrite the nr_spis with the maximum available INTID from eSPI range.
+ * In that case, the number of regular SPIs will be adjusted to the maximum
+ * value during vGIC initialization.
+ */
+ if ( gic_number_espis() > 0 )
+ dom0_cfg.arch.nr_spis = VGIC_DEF_MAX_SPI;
+#endif
So we have almost (?) identical code and big comments in both
create_dom0() and arch_create_domUs().
I was thinking, wouldn't it be better if we put this into a helper? This
way, I think, we will reduce the number of GICv3-specific #ifdef-s in
common domain construction code and will not need to worry about keeping
these places in sync when updating the check/comment.
Something like below to be applied on top of your patch (not build-tested):
diff --git a/xen/arch/arm/dom0less-build.c b/xen/arch/arm/dom0less-build.c
index f4f9077db5..02d5559102 100644
--- a/xen/arch/arm/dom0less-build.c
+++ b/xen/arch/arm/dom0less-build.c
@@ -285,19 +285,7 @@ void __init arch_create_domUs(struct dt_device_node
*node,
{
int vpl011_virq = GUEST_VPL011_SPI;
- d_cfg->arch.nr_spis = VGIC_DEF_NR_SPIS;
-#ifdef CONFIG_GICV3_ESPI
- /*
- * Check if the hardware supports extended SPIs (even if the
- * appropriate config is set). If not, the common SPI range
- * will be used. Otherwise overwrite the nr_spis with the maximum
- * available INTID from eSPI range. In that case, the number of
- * regular SPIs will be adjusted to the maximum value during vGIC
- * initialization.
- */
- if ( gic_number_espis() > 0 )
- d_cfg->arch.nr_spis = VGIC_DEF_MAX_SPI;
-#endif
+ 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 148a8bdb60..39eea0be00 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -2054,18 +2054,7 @@ 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;
- dom0_cfg.arch.nr_spis = VGIC_DEF_NR_SPIS;
-#ifdef CONFIG_GICV3_ESPI
- /*
- * Check if the hardware supports extended SPIs (even if the
appropriate
- * config is set). If not, the common SPI range will be used. Otherwise
- * overwrite the nr_spis with the maximum available INTID from eSPI
range.
- * In that case, the number of regular SPIs will be adjusted to the
maximum
- * value during vGIC initialization.
- */
- if ( gic_number_espis() > 0 )
- dom0_cfg.arch.nr_spis = VGIC_DEF_MAX_SPI;
-#endif
+ 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/include/asm/vgic.h
b/xen/arch/arm/include/asm/vgic.h
index 0bb025f5d5..0350122a74 100644
--- a/xen/arch/arm/include/asm/vgic.h
+++ b/xen/arch/arm/include/asm/vgic.h
@@ -367,6 +367,24 @@ extern void vgic_check_inflight_irqs_pending(struct
vcpu *v,
min(gic_number_espis(), 1024U) - 32)
#endif
+static inline unsigned int vgic_def_nr_spis(void)
+{
+#ifdef CONFIG_GICV3_ESPI
+ /*
+ * Check if the hardware supports extended SPIs (even if the
+ * appropriate config is set). If not, the common SPI range
+ * will be used. Otherwise overwrite the nr_spis with the maximum
+ * available INTID from eSPI range. In that case, the number of
+ * regular SPIs will be adjusted to the maximum value during vGIC
+ * initialization.
+ */
+ if ( gic_number_espis() > 0 )
+ return VGIC_DEF_MAX_SPI;
+#endif
+
+ return VGIC_DEF_NR_SPIS;
+}
+
extern bool vgic_is_valid_line(struct domain *d, unsigned int virq);
static inline bool vgic_is_spi(struct domain *d, unsigned int virq)
******
Also, if VGIC_DEF_MAX_SPI (or whatever name you agreed on) is not
supposed to be used outside of vgic.h, I would even consider dropping it
and using "ESPI_BASE_INTID + min(gic_number_espis(), 1024U) - 32" (to
reduce one more #ifdef in the header).
P.S. I might be wrong, but it feels to me, that description for
"nr_spis" in docs/man/xl.cfg.5.pod.in needs a update within your series
(it mentions that "Max is 960 SPIs").
