Thread (8 messages) 8 messages, 2 authors, 2019-06-29
STALE2544d REVIEWED: 3 (2M)

[PATCH v3 1/5] x86: hv: hyperv-tlfs.h: Create and use Hyper-V page definitions

From: Maya Nakamura <hidden>
Date: 2019-06-18 07:18:59
Also in: lkml
Subsystem: the rest, x86 architecture (32-bit and 64-bit) · Maintainers: Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen

Define HV_HYP_PAGE_SHIFT, HV_HYP_PAGE_SIZE, and HV_HYP_PAGE_MASK because
the Linux guest page size and hypervisor page size concepts are
different, even though they happen to be the same value on x86.

Also, replace PAGE_SIZE with HV_HYP_PAGE_SIZE.

Signed-off-by: Maya Nakamura <redacted>
Reviewed-by: Michael Kelley <redacted>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/include/asm/hyperv-tlfs.h | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index af78cd72b8f3..4097edf552b3 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -12,6 +12,16 @@
 #include <linux/types.h>
 #include <asm/page.h>
 
+/*
+ * While not explicitly listed in the TLFS, Hyper-V always runs with a page size
+ * of 4096. These definitions are used when communicating with Hyper-V using
+ * guest physical pages and guest physical page addresses, since the guest page
+ * size may not be 4096 on all architectures.
+ */
+#define HV_HYP_PAGE_SHIFT	12
+#define HV_HYP_PAGE_SIZE	BIT(HV_HYP_PAGE_SHIFT)
+#define HV_HYP_PAGE_MASK	(~(HV_HYP_PAGE_SIZE - 1))
+
 /*
  * The below CPUID leaves are present if VersionAndFeatures.HypervisorPresent
  * is set by CPUID(HvCpuIdFunctionVersionAndFeatures).
@@ -847,7 +857,7 @@ union hv_gpa_page_range {
  * count is equal with how many entries of union hv_gpa_page_range can
  * be populated into the input parameter page.
  */
-#define HV_MAX_FLUSH_REP_COUNT ((PAGE_SIZE - 2 * sizeof(u64)) /	\
+#define HV_MAX_FLUSH_REP_COUNT ((HV_HYP_PAGE_SIZE - 2 * sizeof(u64)) / \
 				sizeof(union hv_gpa_page_range))
 
 struct hv_guest_mapping_flush_list {
-- 
2.17.1
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