[Xen-changelog] [xen staging] x86/IRQ: flip legacy and dynamic vector ranges

[patchbot@xxxxxxx]

commit 8fb4e83dc3c3825628fff5984b91e8dbb0adc20f
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Fri Dec 27 09:54:19 2019 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Dec 27 09:54:19 2019 +0100

    x86/IRQ: flip legacy and dynamic vector ranges
    
    There's no reason to have the PIC vectors (which are typically entirely
    unused on 64-bit systems anyway) right below the high priority ones. Put
    them in the lowest possible range, and shift the dynamic vector range up
    accordingly. This is to reduce the priority of PIC vectors in the LAPIC
    vs all other ones.
    
    Note that irq_move_cleanup_interrupt(), despite using
    FIRST_DYNAMIC_VECTOR, does not get touched, as PIC interrupts aren't
    movable.
    
    Suggested-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/apic.c                            |  4 ++--
 xen/arch/x86/io_apic.c                         |  4 +++-
 xen/arch/x86/irq.c                             |  2 +-
 xen/arch/x86/x86_64/entry.S                    |  4 ++--
 xen/include/asm-x86/mach-default/irq_vectors.h | 13 ++++++++-----
 5 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/xen/arch/x86/apic.c b/xen/arch/x86/apic.c
index 50f3d305e8..7e84daf32a 100644
--- a/xen/arch/x86/apic.c
+++ b/xen/arch/x86/apic.c
@@ -528,9 +528,9 @@ void setup_local_APIC(void)
     init_apic_ldr();
 
     /*
-     * Set Task Priority to reject any interrupts below FIRST_DYNAMIC_VECTOR.
+     * Set Task Priority to reject any interrupts below FIRST_IRQ_VECTOR.
      */
-    apic_write(APIC_TASKPRI, (FIRST_DYNAMIC_VECTOR & 0xF0) - 0x10);
+    apic_write(APIC_TASKPRI, (FIRST_IRQ_VECTOR & 0xF0) - 0x10);
 
     /*
      * After a crash, we no longer service the interrupts and a pending
diff --git a/xen/arch/x86/io_apic.c b/xen/arch/x86/io_apic.c
index 6238df494b..9913dfde1f 100644
--- a/xen/arch/x86/io_apic.c
+++ b/xen/arch/x86/io_apic.c
@@ -2388,7 +2388,9 @@ int ioapic_guest_write(unsigned long physbase, unsigned 
int reg, u32 val)
         return 0;
     }
 
-    if ( desc->arch.vector <= 0 || desc->arch.vector > LAST_DYNAMIC_VECTOR )
+    if ( desc->arch.vector <= 0 || desc->arch.vector > LAST_DYNAMIC_VECTOR ||
+         (desc->arch.vector >= FIRST_LEGACY_VECTOR &&
+          desc->arch.vector <= LAST_LEGACY_VECTOR) )
     {
         int vector = desc->arch.vector;
 
diff --git a/xen/arch/x86/irq.c b/xen/arch/x86/irq.c
index 9adad3ff04..ae02cf1712 100644
--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -101,7 +101,7 @@ void unlock_vector_lock(void)
 
 static inline bool valid_irq_vector(unsigned int vector)
 {
-    return vector >= FIRST_DYNAMIC_VECTOR && vector <= LAST_HIPRIORITY_VECTOR;
+    return vector >= FIRST_IRQ_VECTOR && vector <= LAST_IRQ_VECTOR;
 }
 
 static void release_old_vec(struct irq_desc *desc)
diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S
index 11385857fa..70c0b1c0a5 100644
--- a/xen/arch/x86/x86_64/entry.S
+++ b/xen/arch/x86/x86_64/entry.S
@@ -923,9 +923,9 @@ autogen_stubs: /* Automatically generated stubs. */
 
         /* Common interrupts, heading towards do_IRQ(). */
 #ifdef CONFIG_PV
-        .if vec >= FIRST_DYNAMIC_VECTOR && vec != HYPERCALL_VECTOR && vec != 
LEGACY_SYSCALL_VECTOR
+        .if vec >= FIRST_IRQ_VECTOR && vec != HYPERCALL_VECTOR && vec != 
LEGACY_SYSCALL_VECTOR
 #else
-        .if vec >= FIRST_DYNAMIC_VECTOR
+        .if vec >= FIRST_IRQ_VECTOR
 #endif
 
         ALIGN
diff --git a/xen/include/asm-x86/mach-default/irq_vectors.h 
b/xen/include/asm-x86/mach-default/irq_vectors.h
index 992e00c44b..6824a9e301 100644
--- a/xen/include/asm-x86/mach-default/irq_vectors.h
+++ b/xen/include/asm-x86/mach-default/irq_vectors.h
@@ -18,20 +18,23 @@
 /* IRQ0 (timer) is statically allocated but must be high priority. */
 #define IRQ0_VECTOR             0xf0
 
-/* Legacy PIC uses vectors 0xe0-0xef. */
-#define FIRST_LEGACY_VECTOR    0xe0
-#define LAST_LEGACY_VECTOR      0xef
+/* Legacy PIC uses vectors 0x20-0x2f. */
+#define FIRST_LEGACY_VECTOR     0x20
+#define LAST_LEGACY_VECTOR      (FIRST_LEGACY_VECTOR + 0xf)
 
 #define HYPERCALL_VECTOR       0x82
 #define LEGACY_SYSCALL_VECTOR   0x80
 
 /* Dynamically-allocated vectors available to any driver. */
-#define FIRST_DYNAMIC_VECTOR   0x20
-#define LAST_DYNAMIC_VECTOR    0xdf
+#define FIRST_DYNAMIC_VECTOR    (LAST_LEGACY_VECTOR + 1)
+#define LAST_DYNAMIC_VECTOR     0xef
 #define NR_DYNAMIC_VECTORS     (LAST_DYNAMIC_VECTOR - FIRST_DYNAMIC_VECTOR + 1)
 
 #define IRQ_MOVE_CLEANUP_VECTOR FIRST_DYNAMIC_VECTOR
 
 #define NR_VECTORS 256
 
+#define FIRST_IRQ_VECTOR        FIRST_LEGACY_VECTOR
+#define LAST_IRQ_VECTOR         LAST_HIPRIORITY_VECTOR
+
 #endif /* _ASM_IRQ_VECTORS_H */
--
generated by git-patchbot for /home/xen/git/xen.git#staging

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