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From: Dexuan Cui <decui@microsoft.com>
To: "arnd@arndb.de" <arnd@arndb.de>, "bp@alien8.de" <bp@alien8.de>,
	"daniel.lezcano@linaro.org" <daniel.lezcano@linaro.org>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	"hpa@zytor.com" <hpa@zytor.com>,
	KY Srinivasan <kys@microsoft.com>,
	"linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"mingo@redhat.com" <mingo@redhat.com>,
	"sashal@kernel.org" <sashal@kernel.org>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	"tglx@linutronix.de" <tglx@linutronix.de>,
	"x86@kernel.org" <x86@kernel.org>,
	Michael Kelley <mikelley@microsoft.com>,
	Sasha Levin <Alexander.Levin@microsoft.com>
Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
	Dexuan Cui <decui@microsoft.com>
Subject: [PATCH v5 1/3] x86/hyper-v: Suspend/resume the hypercall page for hibernation
Date: Thu, 5 Sep 2019 22:47:12 +0000	[thread overview]
Message-ID: <1567723581-29088-2-git-send-email-decui@microsoft.com> (raw)
In-Reply-To: <1567723581-29088-1-git-send-email-decui@microsoft.com>

This is needed for hibernation, e.g. when we resume the old kernel, we need
to disable the "current" kernel's hypercall page and then resume the old
kernel's.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
---
 arch/x86/hyperv/hv_init.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 866dfb3..037b0f3 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -20,6 +20,7 @@
 #include <linux/hyperv.h>
 #include <linux/slab.h>
 #include <linux/cpuhotplug.h>
+#include <linux/syscore_ops.h>
 #include <clocksource/hyperv_timer.h>
 
 void *hv_hypercall_pg;
@@ -223,6 +224,34 @@ static int __init hv_pci_init(void)
 	return 1;
 }
 
+static int hv_suspend(void)
+{
+	union hv_x64_msr_hypercall_contents hypercall_msr;
+
+	/* Reset the hypercall page */
+	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+	hypercall_msr.enable = 0;
+	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+
+	return 0;
+}
+
+static void hv_resume(void)
+{
+	union hv_x64_msr_hypercall_contents hypercall_msr;
+
+	/* Re-enable the hypercall page */
+	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+	hypercall_msr.enable = 1;
+	hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg);
+	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+}
+
+static struct syscore_ops hv_syscore_ops = {
+	.suspend = hv_suspend,
+	.resume = hv_resume,
+};
+
 /*
  * This function is to be invoked early in the boot sequence after the
  * hypervisor has been detected.
@@ -301,6 +330,8 @@ void __init hyperv_init(void)
 
 	x86_init.pci.arch_init = hv_pci_init;
 
+	register_syscore_ops(&hv_syscore_ops);
+
 	return;
 
 remove_cpuhp_state:
@@ -320,6 +351,8 @@ void hyperv_cleanup(void)
 {
 	union hv_x64_msr_hypercall_contents hypercall_msr;
 
+	unregister_syscore_ops(&hv_syscore_ops);
+
 	/* Reset our OS id */
 	wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
 
-- 
1.8.3.1


  reply	other threads:[~2019-09-05 22:47 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-05 22:47 [PATCH v5 0/3] Enhance Hyper-V for hibernation Dexuan Cui
2019-09-05 22:47 ` Dexuan Cui [this message]
2019-09-26 10:44   ` [PATCH v5 1/3] x86/hyper-v: Suspend/resume the hypercall page " Vitaly Kuznetsov
2019-09-27  6:48     ` Dexuan Cui
2019-09-27  9:05       ` Vitaly Kuznetsov
2019-09-30 18:49         ` Dexuan Cui
2019-09-05 22:47 ` [PATCH v5 2/3] x86/hyper-v: Implement hv_is_hibernation_supported() Dexuan Cui
2019-09-05 22:47 ` [PATCH v5 3/3] clocksource/drivers: Suspend/resume Hyper-V clocksource for hibernation Dexuan Cui
2019-09-25 23:21   ` Daniel Lezcano
2019-09-25 23:35     ` Dexuan Cui
2019-09-26 13:16       ` Daniel Lezcano
2019-09-27  5:57         ` Dexuan Cui
2019-09-25 22:49 ` [PATCH v5 0/3] Enhance Hyper-V " Dexuan Cui

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