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From: Michael Kelley <mikelley@microsoft.com>
To: will@kernel.org, ardb@kernel.org, arnd@arndb.de,
	catalin.marinas@arm.com, mark.rutland@arm.com, maz@kernel.org,
	linux-arm-kernel@lists.infradead.org, gregkh@linuxfoundation.org,
	linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org,
	linux-efi@vger.kernel.org, linux-arch@vger.kernel.org,
	wei.liu@kernel.org, vkuznets@redhat.com, kys@microsoft.com
Cc: mikelley@microsoft.com, sunilmut@microsoft.com, boqun.feng@gmail.com
Subject: [PATCH v7 04/10] arm64: hyperv: Add memory alloc/free functions for Hyper-V size pages
Date: Mon, 24 Aug 2020 09:46:17 -0700
Message-ID: <1598287583-71762-5-git-send-email-mikelley@microsoft.com> (raw)
In-Reply-To: <1598287583-71762-1-git-send-email-mikelley@microsoft.com>

Add ARM64-specific code to allocate memory with HV_HYP_PAGE_SIZE
size and alignment. These are for use when pages need to be shared
with Hyper-V. Separate functions are needed as the page size used
by Hyper-V may not be the same as the guest page size.

This code is built only when CONFIG_HYPERV is enabled.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
---
 arch/arm64/hyperv/hv_core.c    | 43 ++++++++++++++++++++++++++++++++++++++++++
 include/asm-generic/mshyperv.h |  5 +++++
 2 files changed, 48 insertions(+)

diff --git a/arch/arm64/hyperv/hv_core.c b/arch/arm64/hyperv/hv_core.c
index 9b35011..14e41b7 100644
--- a/arch/arm64/hyperv/hv_core.c
+++ b/arch/arm64/hyperv/hv_core.c
@@ -24,6 +24,49 @@
 
 
 /*
+ * Functions for allocating and freeing memory with size and
+ * alignment HV_HYP_PAGE_SIZE. These functions are needed because
+ * the guest page size may not be the same as the Hyper-V page
+ * size. We depend upon kmalloc() aligning power-of-two size
+ * allocations to the allocation size boundary, so that the
+ * allocated memory appears to Hyper-V as a page of the size
+ * it expects.
+ *
+ * These functions are used by arm64 specific code as well as
+ * arch independent Hyper-V drivers.
+ */
+
+void *hv_alloc_hyperv_page(void)
+{
+	BUILD_BUG_ON(PAGE_SIZE <  HV_HYP_PAGE_SIZE);
+
+	if (PAGE_SIZE == HV_HYP_PAGE_SIZE)
+		return (void *)__get_free_page(GFP_KERNEL);
+	else
+		return kmalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
+}
+EXPORT_SYMBOL_GPL(hv_alloc_hyperv_page);
+
+void *hv_alloc_hyperv_zeroed_page(void)
+{
+	if (PAGE_SIZE == HV_HYP_PAGE_SIZE)
+		return (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+	else
+		return kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
+}
+EXPORT_SYMBOL_GPL(hv_alloc_hyperv_zeroed_page);
+
+void hv_free_hyperv_page(unsigned long addr)
+{
+	if (PAGE_SIZE == HV_HYP_PAGE_SIZE)
+		free_page(addr);
+	else
+		kfree((void *)addr);
+}
+EXPORT_SYMBOL_GPL(hv_free_hyperv_page);
+
+
+/*
  * hv_do_hypercall- Invoke the specified hypercall
  */
 u64 hv_do_hypercall(u64 control, void *input, void *output)
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index c577996..d345a59 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -101,6 +101,11 @@ static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
 
 extern int vmbus_interrupt;
 
+void *hv_alloc_hyperv_page(void);
+void *hv_alloc_hyperv_zeroed_page(void);
+void hv_free_hyperv_page(unsigned long addr);
+
+
 #if IS_ENABLED(CONFIG_HYPERV)
 /*
  * Hypervisor's notion of virtual processor ID is different from
-- 
1.8.3.1


  parent reply index

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-24 16:46 [PATCH v7 00/10] Enable Linux guests on Hyper-V on ARM64 Michael Kelley
2020-08-24 16:46 ` [PATCH v7 01/10] arm/arm64: smccc-1.1: Add vendor specific owner definition Michael Kelley
2020-08-24 16:46 ` [PATCH v7 02/10] arm64: hyperv: Add core Hyper-V include files Michael Kelley
2020-08-24 18:38   ` Arnd Bergmann
2020-08-24 16:46 ` [PATCH v7 03/10] arm64: hyperv: Add hypercall and register access functions Michael Kelley
2020-08-24 16:46 ` Michael Kelley [this message]
2020-08-24 16:46 ` [PATCH v7 05/10] arm64: hyperv: Add interrupt handlers for VMbus and stimer Michael Kelley
2020-08-24 18:54   ` Arnd Bergmann
2020-08-25 22:04     ` Michael Kelley
2020-08-26  7:14       ` Arnd Bergmann
2020-08-24 16:46 ` [PATCH v7 06/10] arm64: hyperv: Add kexec and panic handlers Michael Kelley
2020-08-24 16:46 ` [PATCH v7 07/10] arm64: hyperv: Initialize hypervisor on boot Michael Kelley
2020-08-24 18:33   ` Arnd Bergmann
2020-08-25 21:20     ` Michael Kelley
2020-08-26  7:18       ` Arnd Bergmann
2020-08-24 16:46 ` [PATCH v7 08/10] Drivers: hv: vmbus: Add hooks for per-CPU IRQ Michael Kelley
2020-08-24 16:46 ` [PATCH v7 09/10] arm64: efi: Export screen_info Michael Kelley
2020-08-24 17:21   ` Ard Biesheuvel
2020-08-24 17:35   ` Greg KH
2020-08-24 17:40     ` Michael Kelley
2020-08-24 17:52       ` Greg KH
2020-08-24 16:46 ` [PATCH v7 10/10] Drivers: hv: Enable Hyper-V code to be built on ARM64 Michael Kelley
2020-08-24 17:24   ` Ard Biesheuvel
2020-08-24 17:28     ` Michael Kelley
2020-08-25  8:47     ` Ben Dooks

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