[PATCH 2 of 4] Linux pvops: early PV on HVM

From: Stefano Stabellini
Date: Tue Mar 02 2010 - 13:26:43 EST


Hi all,
this patch is derived from an earler version of the patch named "Xen PV
extension of HVM initialization" in Shen's patch series.
This patch:

- adds a xen_guest_init hook in setup.c right after kvm_guest_init;

- initializes basic pv on hvm features in xen_guest_init;

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Signed-off-by: Sheng Yang <sheng@xxxxxxxxxxxxxxx>
Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@xxxxxxxxx>

---

diff --git a/arch/x86/include/asm/xen/hypervisor.h b/arch/x86/include/asm/xen/hypervisor.h
index d5b7e90..bbd3f65 100644
--- a/arch/x86/include/asm/xen/hypervisor.h
+++ b/arch/x86/include/asm/xen/hypervisor.h
@@ -33,6 +33,7 @@
#ifndef _ASM_X86_XEN_HYPERVISOR_H
#define _ASM_X86_XEN_HYPERVISOR_H

+#ifdef CONFIG_XEN
/* arch/i386/kernel/setup.c */
extern struct shared_info *HYPERVISOR_shared_info;
extern struct start_info *xen_start_info;
@@ -43,10 +44,11 @@ enum xen_domain_type {
XEN_HVM_DOMAIN, /* running in a Xen hvm domain */
};

-#ifdef CONFIG_XEN
extern enum xen_domain_type xen_domain_type;
+extern void xen_guest_init(void);
#else
#define xen_domain_type XEN_NATIVE
+#define xen_guest_init() do { } while (0)
#endif

#define xen_domain() (xen_domain_type != XEN_NATIVE)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 86bef0f..2e23335 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -113,6 +113,8 @@
#define ARCH_SETUP
#endif

+#include <asm/xen/hypervisor.h>
+
/*
* end_pfn only includes RAM, while max_pfn_mapped includes all e820 entries.
* The direct mapping extends to max_pfn_mapped, so that we can directly access
@@ -1015,6 +1017,7 @@ void __init setup_arch(char **cmdline_p)
probe_nr_irqs_gsi();

kvm_guest_init();
+ xen_guest_init();

e820_reserve_resources();
e820_mark_nosave_regions(max_low_pfn);
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 7a62c2b..460c334 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -32,6 +32,8 @@
#include <xen/interface/version.h>
#include <xen/interface/physdev.h>
#include <xen/interface/vcpu.h>
+#include <xen/interface/memory.h>
+#include <xen/interface/hvm/hvm_op.h>
#include <xen/features.h>
#include <xen/page.h>
#include <xen/hvc-console.h>
@@ -41,6 +43,7 @@
#include <asm/page.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>
+#include <asm/xen/cpuid.h>
#include <asm/fixmap.h>
#include <asm/processor.h>
#include <asm/proto.h>
@@ -1248,3 +1251,86 @@ asmlinkage void __init xen_start_kernel(void)
x86_64_start_reservations((char *)__pa_symbol(&boot_params));
#endif
}
+
+static uint32_t xen_cpuid_base(void)
+{
+ uint32_t base, eax, ebx, ecx, edx;
+ char signature[13];
+
+ for (base = 0x40000000; base < 0x40010000; base += 0x100) {
+ cpuid(base, &eax, &ebx, &ecx, &edx);
+ *(uint32_t*)(signature + 0) = ebx;
+ *(uint32_t*)(signature + 4) = ecx;
+ *(uint32_t*)(signature + 8) = edx;
+ signature[12] = 0;
+
+ if (!strcmp("XenVMMXenVMM", signature) && ((eax - base) >= 2))
+ return base;
+ }
+
+ return 0;
+}
+
+static int init_hvm_pv_info(void)
+{
+ uint32_t eax, ebx, ecx, edx, pages, msr, base;
+ u64 pfn;
+
+ base = xen_cpuid_base();
+ if (!base)
+ return -EINVAL;
+
+ cpuid(base + 1, &eax, &ebx, &ecx, &edx);
+
+ printk(KERN_INFO "Xen version %d.%d.\n", eax >> 16, eax & 0xffff);
+
+ cpuid(base + 2, &pages, &msr, &ecx, &edx);
+
+ /* We only support 1 page of hypercall for now */
+ if (pages != 1)
+ return -ENOMEM;
+
+ pfn = __pa(hypercall_page);
+ wrmsrl(msr, pfn);
+
+ xen_setup_features();
+
+ pv_info = xen_info;
+ pv_info.kernel_rpl = 0;
+
+ xen_domain_type = XEN_HVM_DOMAIN;
+
+ return 0;
+}
+
+static void __init init_shared_info(void)
+{
+ struct xen_add_to_physmap xatp;
+ struct shared_info *shared_info_page;
+
+ shared_info_page = (struct shared_info *) alloc_bootmem_pages(PAGE_SIZE);
+ xatp.domid = DOMID_SELF;
+ xatp.idx = 0;
+ xatp.space = XENMAPSPACE_shared_info;
+ xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
+ if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
+ BUG();
+
+ HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
+
+ /* Don't do the full vcpu_info placement stuff until we have a
+ possible map and a non-dummy shared_info. */
+ per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
+}
+
+void __init xen_guest_init(void)
+{
+ int r;
+
+ r = init_hvm_pv_info();
+ if (r < 0)
+ return;
+
+ init_shared_info();
+}
+
diff --git a/drivers/input/xen-kbdfront.c b/drivers/input/xen-kbdfront.c
index 97cad30..48efbd8 100644
--- a/drivers/input/xen-kbdfront.c
+++ b/drivers/input/xen-kbdfront.c
@@ -344,6 +344,9 @@ static int __init xenkbd_init(void)
if (xen_initial_domain())
return -ENODEV;

+ if (xen_hvm_domain())
+ return -ENODEV;
+
return xenbus_register_frontend(&xenkbd_driver);
}

diff --git a/drivers/video/xen-fbfront.c b/drivers/video/xen-fbfront.c
index 1e2dc9c..77566fb 100644
--- a/drivers/video/xen-fbfront.c
+++ b/drivers/video/xen-fbfront.c
@@ -689,6 +689,9 @@ static int __init xenfb_init(void)
if (xen_initial_domain())
return -ENODEV;

+ if (xen_hvm_domain())
+ return -ENODEV;
+
return xenbus_register_frontend(&xenfb_driver);
}

diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 348d042..c18ae96 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -53,6 +53,8 @@
#include <xen/events.h>
#include <xen/page.h>

+#include <xen/hvm.h>
+
#include "xenbus_comms.h"
#include "xenbus_probe.h"

@@ -722,10 +724,19 @@ static int __init xenbus_probe_init(void)
xen_store_interface = mfn_to_virt(xen_store_mfn);
} else {
xenstored_ready = 1;
- xen_store_evtchn = xen_start_info->store_evtchn;
- xen_store_mfn = xen_start_info->store_mfn;
+ if (xen_hvm_domain()) {
+ xen_store_evtchn =
+ hvm_get_parameter(HVM_PARAM_STORE_EVTCHN);
+ xen_store_mfn =
+ hvm_get_parameter(HVM_PARAM_STORE_PFN);
+ xen_store_interface =
+ ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE);
+ } else {
+ xen_store_evtchn = xen_start_info->store_evtchn;
+ xen_store_mfn = xen_start_info->store_mfn;
+ xen_store_interface = mfn_to_virt(xen_store_mfn);
+ }
}
- xen_store_interface = mfn_to_virt(xen_store_mfn);

/* Initialize the interface to xenstore. */
err = xs_init();
--
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