From: Jan Kiszka <jan.kiszka@siemens.com>
Date: Sat, 5 Mar 2016 19:43:28 +0000 (+0100)
Subject: x86: Factor out iommu_select_fault_reporting_cpu
X-Git-Url: https://rtime.felk.cvut.cz/gitweb/jailhouse.git/commitdiff_plain/4127cb50604f7adb38a23dcbf7d0d634215c8aa0

x86: Factor out iommu_select_fault_reporting_cpu

The logic to pick a root cell CPU for IOMMU fault reporting will be
reused for AMD. Factor it out.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---

diff --git a/hypervisor/arch/x86/include/asm/iommu.h b/hypervisor/arch/x86/include/asm/iommu.h
index 9cc4f73..b667576 100644
--- a/hypervisor/arch/x86/include/asm/iommu.h
+++ b/hypervisor/arch/x86/include/asm/iommu.h
@@ -21,6 +21,8 @@
 #include <asm/apic.h>
 #include <asm/percpu.h>
 
+extern unsigned int fault_reporting_cpu_id;
+
 unsigned int iommu_count_units(void);
 unsigned int iommu_mmio_count_regions(struct cell *cell);
 
@@ -49,6 +51,7 @@ void iommu_config_commit(struct cell *cell_added_removed);
 
 void iommu_shutdown(void);
 
+struct per_cpu *iommu_select_fault_reporting_cpu(void);
 void iommu_check_pending_faults(void);
 
 bool iommu_cell_emulates_ir(struct cell *cell);
diff --git a/hypervisor/arch/x86/iommu.c b/hypervisor/arch/x86/iommu.c
index 11f35bc..d86d8f9 100644
--- a/hypervisor/arch/x86/iommu.c
+++ b/hypervisor/arch/x86/iommu.c
@@ -13,6 +13,8 @@
 #include <jailhouse/control.h>
 #include <asm/iommu.h>
 
+unsigned int fault_reporting_cpu_id;
+
 unsigned int iommu_count_units(void)
 {
 	unsigned int units = 0;
@@ -22,3 +24,21 @@ unsigned int iommu_count_units(void)
 		units++;
 	return units;
 }
+
+struct per_cpu *iommu_select_fault_reporting_cpu(void)
+{
+	struct per_cpu *cpu_data;
+	unsigned int n;
+
+	/* This assumes that at least one bit is set somewhere because we
+	 * don't support configurations where Linux is left with no CPUs. */
+	for (n = 0; root_cell.cpu_set->bitmap[n] == 0; n++)
+		/* Empty loop */;
+	cpu_data = per_cpu(ffsl(root_cell.cpu_set->bitmap[n]));
+
+	/* Save this value globally to avoid multiple reports of the same
+	 * case from different CPUs */
+	fault_reporting_cpu_id = cpu_data->cpu_id;
+
+	return cpu_data;
+}
diff --git a/hypervisor/arch/x86/vtd.c b/hypervisor/arch/x86/vtd.c
index f65dac9..d9b9644 100644
--- a/hypervisor/arch/x86/vtd.c
+++ b/hypervisor/arch/x86/vtd.c
@@ -199,7 +199,6 @@ static void *unit_inv_queue;
 static unsigned int dmar_units;
 static unsigned int dmar_pt_levels;
 static unsigned int dmar_num_did = ~0U;
-static unsigned int fault_reporting_cpu_id;
 static DEFINE_SPINLOCK(inv_queue_lock);
 static struct vtd_emulation root_cell_units[JAILHOUSE_MAX_IOMMU_UNITS];
 static bool dmar_units_initialized;
@@ -298,19 +297,12 @@ static void vtd_init_fault_nmi(void)
 	struct per_cpu *cpu_data;
 	unsigned int n;
 
-	/* This assumes that at least one bit is set somewhere because we
-	 * don't support configurations where Linux is left with no CPUs. */
-	for (n = 0; root_cell.cpu_set->bitmap[n] == 0; n++)
-		/* Empty loop */;
-	cpu_data = per_cpu(ffsl(root_cell.cpu_set->bitmap[n]));
+	/* Pick a suitable root cell CPU to report faults. */
+	cpu_data = iommu_select_fault_reporting_cpu();
 
 	/* We only support 8-bit APIC IDs. */
 	msi.native.destination = (u8)cpu_data->apic_id;
 
-	/* Save this value globally to avoid multiple reports of the same
-	 * case from different CPUs */
-	fault_reporting_cpu_id = cpu_data->cpu_id;
-
 	for (n = 0; n < dmar_units; n++, reg_base += DMAR_MMIO_SIZE) {
 		/* Mask events */
 		mmio_write32_field(reg_base + VTD_FECTL_REG, VTD_FECTL_IM, 1);