[xen] Add basic support for PV-HVM domains

Add basic support for Xen PV-HVM domains (detected via the Xen
platform PCI device with IDs 5853:0001), including support for
accessing configuration via XenStore and enumerating devices via
XenBus.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

2 files changed, 165 insertions, 0 deletions

diff --git a/src/arch/x86/include/bits/errfile.h b/src/arch/x86/include/bits/errfile.h
index acf8c3e39..624575621 100644
--- a/src/arch/x86/include/bits/errfile.h
+++ b/src/arch/x86/include/bits/errfile.h
@@ -45,6 +45,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 
 #define ERRFILE_timer_rdtsc   ( ERRFILE_ARCH | ERRFILE_DRIVER | 0x00000000 )
 #define ERRFILE_timer_bios    ( ERRFILE_ARCH | ERRFILE_DRIVER | 0x00010000 )
+#define ERRFILE_hvm	      ( ERRFILE_ARCH | ERRFILE_DRIVER | 0x00020000 )
 
 #define ERRFILE_cpuid_cmd      ( ERRFILE_ARCH | ERRFILE_OTHER | 0x00000000 )
 #define ERRFILE_cpuid_settings ( ERRFILE_ARCH | ERRFILE_OTHER | 0x00010000 )
diff --git a/src/arch/x86/include/bits/xen.h b/src/arch/x86/include/bits/xen.h
new file mode 100644
index 000000000..dbccf1b77
--- /dev/null
+++ b/src/arch/x86/include/bits/xen.h
@@ -0,0 +1,164 @@
+#ifndef _BITS_XEN_H
+#define _BITS_XEN_H
+
+/** @file
+ *
+ * Xen interface
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/* Hypercall registers */
+#ifdef __x86_64__
+#define XEN_REG1 "rdi"
+#define XEN_REG2 "rsi"
+#define XEN_REG3 "rdx"
+#define XEN_REG4 "r10"
+#define XEN_REG5 "r8"
+#else
+#define XEN_REG1 "ebx"
+#define XEN_REG2 "ecx"
+#define XEN_REG3 "edx"
+#define XEN_REG4 "esi"
+#define XEN_REG5 "edi"
+#endif
+
+/** A hypercall entry point */
+struct xen_hypercall {
+	/** Code generated by hypervisor */
+	uint8_t code[32];
+} __attribute__ (( packed ));
+
+/**
+ * Issue hypercall with one argument
+ *
+ * @v xen		Xen hypervisor
+ * @v hypercall		Hypercall number
+ * @v arg1		First argument
+ * @ret retval		Return value
+ */
+static inline __attribute__ (( always_inline )) unsigned long
+xen_hypercall_1 ( struct xen_hypervisor *xen, unsigned int hypercall,
+		  unsigned long arg1 ) {
+	register unsigned long reg1 asm ( XEN_REG1 ) = arg1;
+	unsigned long retval;
+
+	__asm__ __volatile__ ( "call *%2"
+			       : "=a" ( retval ), "+r" ( reg1 )
+			       : "r" ( &xen->hypercall[hypercall] )
+			       : XEN_REG2, XEN_REG3, XEN_REG4, XEN_REG5,
+				 "memory" );
+	return retval;
+}
+
+/**
+ * Issue hypercall with two arguments
+ *
+ * @v xen		Xen hypervisor
+ * @v hypercall		Hypercall number
+ * @v arg1		First argument
+ * @v arg2		Second argument
+ * @ret retval		Return value
+ */
+static inline __attribute__ (( always_inline )) unsigned long
+xen_hypercall_2 ( struct xen_hypervisor *xen, unsigned int hypercall,
+		  unsigned long arg1, unsigned long arg2 ) {
+	register unsigned long reg1 asm ( XEN_REG1 ) = arg1;
+	register unsigned long reg2 asm ( XEN_REG2 ) = arg2;
+	unsigned long retval;
+
+	__asm__ __volatile__ ( "call *%3"
+			       : "=a" ( retval ), "+r" ( reg1 ), "+r" ( reg2 )
+			       : "r" ( &xen->hypercall[hypercall] )
+			       : XEN_REG3, XEN_REG4, XEN_REG5, "memory" );
+	return retval;
+}
+
+/**
+ * Issue hypercall with three arguments
+ *
+ * @v xen		Xen hypervisor
+ * @v hypercall		Hypercall number
+ * @v arg1		First argument
+ * @v arg2		Second argument
+ * @v arg3		Third argument
+ * @ret retval		Return value
+ */
+static inline __attribute__ (( always_inline )) unsigned long
+xen_hypercall_3 ( struct xen_hypervisor *xen, unsigned int hypercall,
+		  unsigned long arg1, unsigned long arg2, unsigned long arg3 ) {
+	register unsigned long reg1 asm ( XEN_REG1 ) = arg1;
+	register unsigned long reg2 asm ( XEN_REG2 ) = arg2;
+	register unsigned long reg3 asm ( XEN_REG3 ) = arg3;
+	unsigned long retval;
+
+	__asm__ __volatile__ ( "call *%4"
+			       : "=a" ( retval ), "+r" ( reg1 ), "+r" ( reg2 ),
+				 "+r" ( reg3 )
+			       : "r" ( &xen->hypercall[hypercall] )
+			       : XEN_REG4, XEN_REG5, "memory" );
+	return retval;
+}
+
+/**
+ * Issue hypercall with four arguments
+ *
+ * @v xen		Xen hypervisor
+ * @v hypercall		Hypercall number
+ * @v arg1		First argument
+ * @v arg2		Second argument
+ * @v arg3		Third argument
+ * @v arg4		Fourth argument
+ * @ret retval		Return value
+ */
+static inline __attribute__ (( always_inline )) unsigned long
+xen_hypercall_4 ( struct xen_hypervisor *xen, unsigned int hypercall,
+		  unsigned long arg1, unsigned long arg2, unsigned long arg3,
+		  unsigned long arg4 ) {
+	register unsigned long reg1 asm ( XEN_REG1 ) = arg1;
+	register unsigned long reg2 asm ( XEN_REG2 ) = arg2;
+	register unsigned long reg3 asm ( XEN_REG3 ) = arg3;
+	register unsigned long reg4 asm ( XEN_REG4 ) = arg4;
+	unsigned long retval;
+
+	__asm__ __volatile__ ( "call *%5"
+			       : "=a" ( retval ), "+r" ( reg1 ), "+r" ( reg2 ),
+				 "+r" ( reg3 ), "+r" ( reg4 )
+			       : "r" ( &xen->hypercall[hypercall] )
+			       : XEN_REG5, "memory" );
+	return retval;
+}
+
+/**
+ * Issue hypercall with five arguments
+ *
+ * @v xen		Xen hypervisor
+ * @v hypercall		Hypercall number
+ * @v arg1		First argument
+ * @v arg2		Second argument
+ * @v arg3		Third argument
+ * @v arg4		Fourth argument
+ * @v arg5		Fifth argument
+ * @ret retval		Return value
+ */
+static inline __attribute__ (( always_inline )) unsigned long
+xen_hypercall_5 ( struct xen_hypervisor *xen, unsigned int hypercall,
+		  unsigned long arg1, unsigned long arg2, unsigned long arg3,
+		  unsigned long arg4, unsigned long arg5 ) {
+	register unsigned long reg1 asm ( XEN_REG1 ) = arg1;
+	register unsigned long reg2 asm ( XEN_REG2 ) = arg2;
+	register unsigned long reg3 asm ( XEN_REG3 ) = arg3;
+	register unsigned long reg4 asm ( XEN_REG4 ) = arg4;
+	register unsigned long reg5 asm ( XEN_REG5 ) = arg5;
+	unsigned long retval;
+
+	__asm__ __volatile__ ( "call *%6"
+			       : "=a" ( retval ), "+r" ( reg1 ), "+r" ( reg2 ),
+				 "+r" ( reg3 ), "+r" ( reg4 ), "+r" ( reg5 )
+			       : "r" ( &xen->hypercall[hypercall] )
+			       : "memory" );
+	return retval;
+}
+
+#endif /* _BITS_XEN_H */