[PATCH v7 01/19] xen: add PV/PVH kernel entry point

From: Roger Pau Monne <roger.pau_at_citrix.com>
Date: Thu, 19 Dec 2013 19:54:38 +0100
Add the PV/PVH entry point and the low level functions for PVH
initialization.
---
 sys/amd64/amd64/locore.S     |   53 +++++++++++++++++++++++++++++++
 sys/amd64/amd64/machdep.c    |   72 ++++++++++++++++++++++++++++++++++++++++++
 sys/amd64/include/asmacros.h |   26 +++++++++++++++
 sys/i386/xen/xen_machdep.c   |    2 +
 sys/x86/xen/hvm.c            |    1 +
 sys/xen/xen-os.h             |    4 ++
 6 files changed, 158 insertions(+), 0 deletions(-)

diff --git a/sys/amd64/amd64/locore.S b/sys/amd64/amd64/locore.S
index 55cda3a..e04cc48 100644
--- a/sys/amd64/amd64/locore.S
+++ b/sys/amd64/amd64/locore.S
_at__at_ -31,6 +31,12 _at__at_
 #include <machine/pmap.h>
 #include <machine/specialreg.h>
 
+#ifdef XENHVM
+#include <xen/xen-os.h>
+#define __ASSEMBLY__
+#include <xen/interface/elfnote.h>
+#endif
+
 #include "assym.s"
 
 /*
_at__at_ -86,3 +92,50 _at__at_ NON_GPROF_ENTRY(btext)
 	ALIGN_DATA			/* just to be sure */
 	.space	0x1000			/* space for bootstack - temporary stack */
 bootstack:
+
+#ifdef XENHVM
+/* Xen */
+.section __xen_guest
+	ELFNOTE(Xen, XEN_ELFNOTE_GUEST_OS,       .asciz, "FreeBSD")
+	ELFNOTE(Xen, XEN_ELFNOTE_GUEST_VERSION,  .asciz, "HEAD")
+	ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION,    .asciz, "xen-3.0")
+	ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      .quad,  KERNBASE)
+	ELFNOTE(Xen, XEN_ELFNOTE_PADDR_OFFSET,   .quad,  KERNBASE) /* Xen honours elf->p_paddr; compensate for this */
+	ELFNOTE(Xen, XEN_ELFNOTE_ENTRY,          .quad,  xen_start)
+	ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, .quad,	 hypercall_page)
+	ELFNOTE(Xen, XEN_ELFNOTE_HV_START_LOW,   .quad,  HYPERVISOR_VIRT_START)
+	ELFNOTE(Xen, XEN_ELFNOTE_FEATURES,       .asciz, "writable_descriptor_tables|auto_translated_physmap|supervisor_mode_kernel|hvm_callback_vector")
+	ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE,       .asciz, "yes")
+	ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID,   .long,  PG_V, PG_V)
+	ELFNOTE(Xen, XEN_ELFNOTE_LOADER,         .asciz, "generic")
+	ELFNOTE(Xen, XEN_ELFNOTE_SUSPEND_CANCEL, .long,  0)
+	ELFNOTE(Xen, XEN_ELFNOTE_BSD_SYMTAB,	 .asciz, "yes")
+
+	.text
+.p2align PAGE_SHIFT, 0x90	/* Hypercall_page needs to be PAGE aligned */
+
+NON_GPROF_ENTRY(hypercall_page)
+	.skip	0x1000, 0x90	/* Fill with "nop"s */
+
+NON_GPROF_ENTRY(xen_start)
+	/* Don't trust what the loader gives for rflags. */
+	pushq	$PSL_KERNEL
+	popfq
+
+	/* Parameters for the xen init function */
+	movq	%rsi, %rdi		/* shared_info (arg 1) */
+	movq	%rsp, %rsi		/* xenstack    (arg 2) */
+
+	/* Use our own stack */
+	movq	$bootstack,%rsp
+	xorl	%ebp, %ebp
+
+	/* u_int64_t hammer_time_xen(start_info_t *si, u_int64_t xenstack); */
+	call	hammer_time_xen
+	movq	%rax, %rsp		/* set up kstack for mi_startup() */
+	call	mi_startup		/* autoconfiguration, mountroot etc */
+
+	/* NOTREACHED */
+0:	hlt
+	jmp 	0b
+#endif
diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index eae657b..a73e33e 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
_at__at_ -146,10 +146,17 _at__at_ __FBSDID("$FreeBSD$");
 #include <isa/isareg.h>
 #include <isa/rtc.h>
 
+#ifdef XENHVM
+#include <xen/xen-os.h>
+#endif
+
 /* Sanity check for __curthread() */
 CTASSERT(offsetof(struct pcpu, pc_curthread) == 0);
 
 extern u_int64_t hammer_time(u_int64_t, u_int64_t);
+#ifdef XENHVM
+extern u_int64_t hammer_time_xen(start_info_t *, u_int64_t);
+#endif
 
 extern void printcpuinfo(void);	/* XXX header file */
 extern void identify_cpu(void);
_at__at_ -1683,6 +1690,71 _at__at_ do_next:
 	msgbufp = (struct msgbuf *)PHYS_TO_DMAP(phys_avail[pa_indx]);
 }
 
+#ifdef XENHVM
+/*
+ * First function called by the Xen PVH boot sequence.
+ *
+ * Set some Xen global variables and prepare the environment so it is
+ * as similar as possible to what native FreeBSD init function expects.
+ */
+u_int64_t
+hammer_time_xen(start_info_t *si, u_int64_t xenstack)
+{
+	u_int64_t physfree;
+	u_int64_t *PT4 = (u_int64_t *)xenstack;
+	u_int64_t *PT3 = (u_int64_t *)(xenstack + PAGE_SIZE);
+	u_int64_t *PT2 = (u_int64_t *)(xenstack + 2 * PAGE_SIZE);
+	int i;
+
+	KASSERT((si != NULL && xenstack != 0),
+	        ("invalid start_info or xenstack"));
+
+	/* We use 3 pages of xen stack for the boot pagetables */
+	physfree = xenstack + 3 * PAGE_SIZE - KERNBASE;
+
+	/* Setup Xen global variables */
+	HYPERVISOR_start_info = si;
+	HYPERVISOR_shared_info =
+		(shared_info_t *)(si->shared_info + KERNBASE);
+
+	/*
+	 * Setup some misc global variables for Xen devices
+	 *
+	 * XXX: devices that need this specific variables should
+	 *      be rewritten to fetch this info by themselves from the
+	 *      start_info page.
+	 */
+	xen_store = (struct xenstore_domain_interface *)
+	            (ptoa(si->store_mfn) + KERNBASE);
+
+	xen_domain_type = XEN_PV_DOMAIN;
+	vm_guest = VM_GUEST_XEN;
+
+	/*
+	 * Use the stack Xen gives us to build the page tables
+	 * as native FreeBSD expects to find them (created
+	 * by the boot trampoline).
+	 */
+	for (i = 0; i < 512; i++) {
+		/* Each slot of the level 4 pages points to the same level 3 page */
+		PT4[i] = ((u_int64_t)&PT3[0]) - KERNBASE;
+		PT4[i] |= PG_V | PG_RW | PG_U;
+
+		/* Each slot of the level 3 pages points to the same level 2 page */
+		PT3[i] = ((u_int64_t)&PT2[0]) - KERNBASE;
+		PT3[i] |= PG_V | PG_RW | PG_U;
+
+		/* The level 2 page slots are mapped with 2MB pages for 1GB. */
+		PT2[i] = i * (2 * 1024 * 1024);
+		PT2[i] |= PG_V | PG_RW | PG_PS | PG_U;
+	}
+	load_cr3(((u_int64_t)&PT4[0]) - KERNBASE);
+
+	/* Now we can jump into the native init function */
+	return (hammer_time(0, physfree));
+}
+#endif
+
 u_int64_t
 hammer_time(u_int64_t modulep, u_int64_t physfree)
 {
diff --git a/sys/amd64/include/asmacros.h b/sys/amd64/include/asmacros.h
index 1fb592a..ce8dce4 100644
--- a/sys/amd64/include/asmacros.h
+++ b/sys/amd64/include/asmacros.h
_at__at_ -201,4 +201,30 _at__at_
 
 #endif /* LOCORE */
 
+#ifdef __STDC__
+#define ELFNOTE(name, type, desctype, descdata...) \
+.pushsection .note.name                 ;       \
+  .align 4                              ;       \
+  .long 2f - 1f         /* namesz */    ;       \
+  .long 4f - 3f         /* descsz */    ;       \
+  .long type                            ;       \
+1:.asciz #name                          ;       \
+2:.align 4                              ;       \
+3:desctype descdata                     ;       \
+4:.align 4                              ;       \
+.popsection
+#else /* !__STDC__, i.e. -traditional */
+#define ELFNOTE(name, type, desctype, descdata) \
+.pushsection .note.name                 ;       \
+  .align 4                              ;       \
+  .long 2f - 1f         /* namesz */    ;       \
+  .long 4f - 3f         /* descsz */    ;       \
+  .long type                            ;       \
+1:.asciz "name"                         ;       \
+2:.align 4                              ;       \
+3:desctype descdata                     ;       \
+4:.align 4                              ;       \
+.popsection
+#endif /* __STDC__ */
+
 #endif /* !_MACHINE_ASMACROS_H_ */
diff --git a/sys/i386/xen/xen_machdep.c b/sys/i386/xen/xen_machdep.c
index 7049be6..fd575ee 100644
--- a/sys/i386/xen/xen_machdep.c
+++ b/sys/i386/xen/xen_machdep.c
_at__at_ -89,6 +89,7 _at__at_ IDTVEC(div), IDTVEC(dbg), IDTVEC(nmi), IDTVEC(bpt), IDTVEC(ofl),
 
 int xendebug_flags; 
 start_info_t *xen_start_info;
+start_info_t *HYPERVISOR_start_info;
 shared_info_t *HYPERVISOR_shared_info;
 xen_pfn_t *xen_machine_phys = machine_to_phys_mapping;
 xen_pfn_t *xen_phys_machine;
_at__at_ -927,6 +928,7 _at__at_ initvalues(start_info_t *startinfo)
 	HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments_notify);	
 #endif	
 	xen_start_info = startinfo;
+	HYPERVISOR_start_info = startinfo;
 	xen_phys_machine = (xen_pfn_t *)startinfo->mfn_list;
 
 	IdlePTD = (pd_entry_t *)((uint8_t *)startinfo->pt_base + PAGE_SIZE);
diff --git a/sys/x86/xen/hvm.c b/sys/x86/xen/hvm.c
index 72811dc..b397721 100644
--- a/sys/x86/xen/hvm.c
+++ b/sys/x86/xen/hvm.c
_at__at_ -159,6 +159,7 _at__at_ DPCPU_DEFINE(xen_intr_handle_t, ipi_handle[nitems(xen_ipis)]);
 /** Hypercall table accessed via HYPERVISOR_*_op() methods. */
 char *hypercall_stubs;
 shared_info_t *HYPERVISOR_shared_info;
+start_info_t *HYPERVISOR_start_info;
 
 #ifdef SMP
 /*---------------------------- XEN PV IPI Handlers ---------------------------*/
diff --git a/sys/xen/xen-os.h b/sys/xen/xen-os.h
index 87644e9..c7474d8 100644
--- a/sys/xen/xen-os.h
+++ b/sys/xen/xen-os.h
_at__at_ -51,6 +51,10 _at__at_
 void force_evtchn_callback(void);
 
 extern shared_info_t *HYPERVISOR_shared_info;
+extern start_info_t *HYPERVISOR_start_info;
+
+/* XXX: we need to get rid of this and use HYPERVISOR_start_info directly */
+extern struct xenstore_domain_interface *xen_store;
 
 enum xen_domain_type {
 	XEN_NATIVE,             /* running on bare hardware    */
-- 
1.7.7.5 (Apple Git-26)
Received on Thu Dec 19 2013 - 17:55:24 UTC

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