vtd: Fix check for interrupt remapping of ioapic RTE

For IOAPIC interrupt remapping, it only needs to remap ioapci RTE,
should not remap other IOAPIC registers, which are IOAPIC ID, VERSION
and Arbitration ID. This patch adds the check for this and only remap
ioapci RTE.

Signed-off-by: Anthony Xu <anthony.xu@intel.com>
Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>

diff --git a/xen/include/asm-x86/io_apic.h b/xen/include/asm-x86/io_apic.h
index 59f8e0712ee4443024e6051aaccd0297d3d0edfa..5964521592c985d32254d1a55ccf14b8c4871147 100644 (file)
--- a/xen/include/asm-x86/io_apic.h
+++ b/xen/include/asm-x86/io_apic.h
@@ -123,9 +123,12 @@ extern struct mpc_config_intsrc mp_irqs[MAX_IRQ_SOURCES];
 /* non-0 if default (table-less) MP configuration */
 extern int mpc_default_type;
 
+/* Only need to remap ioapic RTE (reg: 10~3Fh) */
+#define ioapic_reg_remapped(reg) (iommu_enabled && ((reg) >= 0x10))
+
 static inline unsigned int io_apic_read(unsigned int apic, unsigned int reg)
 {
-       if (iommu_enabled)
+       if (ioapic_reg_remapped(reg))
                return io_apic_read_remap_rte(apic, reg);
        *IO_APIC_BASE(apic) = reg;
        return *(IO_APIC_BASE(apic)+4);
@@ -133,7 +136,7 @@ static inline unsigned int io_apic_read(unsigned int apic, unsigned int reg)
 
 static inline void io_apic_write(unsigned int apic, unsigned int reg, unsigned int value)
 {
-       if (iommu_enabled)
+       if (ioapic_reg_remapped(reg))
                return iommu_update_ire_from_apic(apic, reg, value);
        *IO_APIC_BASE(apic) = reg;
        *(IO_APIC_BASE(apic)+4) = value;
@@ -152,7 +155,7 @@ extern int sis_apic_bug;
 #endif
 static inline void io_apic_modify(unsigned int apic, unsigned int reg, unsigned int value)
 {
-       if (iommu_enabled)
+       if (ioapic_reg_remapped(reg))
                return iommu_update_ire_from_apic(apic, reg, value);
        if (sis_apic_bug)
                *IO_APIC_BASE(apic) = reg;