linux-kernel - [PATCH v2 4/8] KVM: x86/mmu: Dedup macros for computing various page table masks

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Message-Id: <20220614233328.3896033-5-seanjc@google.com>
Date:   Tue, 14 Jun 2022 23:33:24 +0000
From:   Sean Christopherson <seanjc@...gle.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Lai Jiangshan <jiangshan.ljs@...group.com>
Subject: [PATCH v2 4/8] KVM: x86/mmu: Dedup macros for computing various page
 table masks

Provide common helper macros to generate various masks, shifts, etc...
for 32-bit vs. 64-bit page tables.  Only the inputs differ, the actual
calculations are identical.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/mmu.h              |  4 ++--
 arch/x86/kvm/mmu/mmu.c          | 14 +++++---------
 arch/x86/kvm/mmu/mmu_internal.h | 14 ++++++++++++++
 arch/x86/kvm/mmu/paging.h       |  9 +++++----
 arch/x86/kvm/mmu/spte.h         |  7 +++----
 5 files changed, 29 insertions(+), 19 deletions(-)

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index d1021e34ac15..6efe6bd7fb6e 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -7,9 +7,9 @@
 #include "cpuid.h"
 
 #define PT64_PT_BITS 9
-#define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
+#define PT64_ENT_PER_PAGE __PT_ENT_PER_PAGE(PT64_PT_BITS)
 #define PT32_PT_BITS 10
-#define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)
+#define PT32_ENT_PER_PAGE __PT_ENT_PER_PAGE(PT32_PT_BITS)
 
 #define PT_WRITABLE_SHIFT 1
 #define PT_USER_SHIFT 2
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 73497da1a99b..b3edff05a53a 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -113,21 +113,17 @@ module_param(dbg, bool, 0644);
 
 #define PT32_LEVEL_BITS 10
 
-#define PT32_LEVEL_SHIFT(level) \
-		(PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
+#define PT32_LEVEL_SHIFT(level) __PT_LEVEL_SHIFT(level, PT32_LEVEL_BITS)
 
 #define PT32_LVL_OFFSET_MASK(level) \
-	(PT32_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
-						* PT32_LEVEL_BITS))) - 1))
-
-#define PT32_INDEX(address, level)\
-	(((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
+	__PT_LVL_OFFSET_MASK(PT32_BASE_ADDR_MASK, level, PT32_LEVEL_BITS)
 
+#define PT32_INDEX(address, level) __PT_INDEX(address, level, PT32_LEVEL_BITS)
 
 #define PT32_BASE_ADDR_MASK PAGE_MASK
+
 #define PT32_LVL_ADDR_MASK(level) \
-	(PAGE_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
-					    * PT32_LEVEL_BITS))) - 1))
+	__PT_LVL_ADDR_MASK(PT32_BASE_ADDR_MASK, level, PT32_LEVEL_BITS)
 
 #include <trace/events/kvm.h>
 
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index bd2a26897b97..5e1e3c8f8aaa 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -20,6 +20,20 @@ extern bool dbg;
 #define MMU_WARN_ON(x) do { } while (0)
 #endif
 
+/* Page table builder macros common to shadow (host) PTEs and guest PTEs. */
+#define __PT_LEVEL_SHIFT(level, bits_per_level)	\
+	(PAGE_SHIFT + ((level) - 1) * (bits_per_level))
+#define __PT_INDEX(address, level, bits_per_level) \
+	(((address) >> __PT_LEVEL_SHIFT(level, bits_per_level)) & ((1 << (bits_per_level)) - 1))
+
+#define __PT_LVL_ADDR_MASK(base_addr_mask, level, bits_per_level) \
+	((base_addr_mask) & ~((1ULL << (PAGE_SHIFT + (((level) - 1) * (bits_per_level)))) - 1))
+
+#define __PT_LVL_OFFSET_MASK(base_addr_mask, level, bits_per_level) \
+	((base_addr_mask) & ((1ULL << (PAGE_SHIFT + (((level) - 1) * (bits_per_level)))) - 1))
+
+#define __PT_ENT_PER_PAGE(bits_per_level)  (1 << (bits_per_level))
+
 /*
  * Unlike regular MMU roots, PAE "roots", a.k.a. PDPTEs/PDPTRs, have a PRESENT
  * bit, and thus are guaranteed to be non-zero when valid.  And, when a guest
diff --git a/arch/x86/kvm/mmu/paging.h b/arch/x86/kvm/mmu/paging.h
index de8ab323bb70..23f3f64b8092 100644
--- a/arch/x86/kvm/mmu/paging.h
+++ b/arch/x86/kvm/mmu/paging.h
@@ -4,11 +4,12 @@
 #define __KVM_X86_PAGING_H
 
 #define GUEST_PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
+
 #define PT64_LVL_ADDR_MASK(level) \
-	(GUEST_PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
-						* PT64_LEVEL_BITS))) - 1))
+	__PT_LVL_ADDR_MASK(GUEST_PT64_BASE_ADDR_MASK, level, PT64_LEVEL_BITS)
+
 #define PT64_LVL_OFFSET_MASK(level) \
-	(GUEST_PT64_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
-						* PT64_LEVEL_BITS))) - 1))
+	__PT_LVL_OFFSET_MASK(GUEST_PT64_BASE_ADDR_MASK, level, PT64_LEVEL_BITS)
+
 #endif /* __KVM_X86_PAGING_H */
 
diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h
index 0127bb6e3c7d..d5a8183b7232 100644
--- a/arch/x86/kvm/mmu/spte.h
+++ b/arch/x86/kvm/mmu/spte.h
@@ -55,11 +55,10 @@ static_assert(SPTE_TDP_AD_ENABLED_MASK == 0);
 
 #define PT64_LEVEL_BITS 9
 
-#define PT64_LEVEL_SHIFT(level) \
-		(PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
+#define PT64_LEVEL_SHIFT(level) __PT_LEVEL_SHIFT(level, PT64_LEVEL_BITS)
+
+#define PT64_INDEX(address, level) __PT_INDEX(address, level, PT64_LEVEL_BITS)
 
-#define PT64_INDEX(address, level)\
-	(((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
 #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
 
 /*
-- 
2.36.1.476.g0c4daa206d-goog