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From: Juergen Gross <jgross@suse.com>
To: xen-devel@lists.xenproject.org, x86@kernel.org,
	virtualization@lists.linux-foundation.org,
	linux-kernel@vger.kernel.org
Cc: Juergen Gross <jgross@suse.com>, Deep Shah <sdeep@vmware.com>,
	"VMware, Inc." <pv-drivers@vmware.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>
Subject: [PATCH v4 6/6] x86/paravirt: avoid needless paravirt step clearing page table entries
Date: Sat, 15 Aug 2020 12:06:41 +0200	[thread overview]
Message-ID: <20200815100641.26362-7-jgross@suse.com> (raw)
In-Reply-To: <20200815100641.26362-1-jgross@suse.com>

pte_clear() et al are based on tw0 paravirt steps today: one step to
create a page table entry with all zeroes, and one step to write this
entry value.

Drop the first step as it is completely useless.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 arch/x86/include/asm/paravirt.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index f0464b88ea1e..d25cc6830e89 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -448,7 +448,7 @@ static inline pudval_t pud_val(pud_t pud)
 
 static inline void pud_clear(pud_t *pudp)
 {
-	set_pud(pudp, __pud(0));
+	set_pud(pudp, native_make_pud(0));
 }
 
 static inline void set_p4d(p4d_t *p4dp, p4d_t p4d)
@@ -485,15 +485,15 @@ static inline void __set_pgd(pgd_t *pgdp, pgd_t pgd)
 } while (0)
 
 #define pgd_clear(pgdp) do {						\
-	if (pgtable_l5_enabled())						\
-		set_pgd(pgdp, __pgd(0));				\
+	if (pgtable_l5_enabled())					\
+		set_pgd(pgdp, native_make_pgd(0));			\
 } while (0)
 
 #endif  /* CONFIG_PGTABLE_LEVELS == 5 */
 
 static inline void p4d_clear(p4d_t *p4dp)
 {
-	set_p4d(p4dp, __p4d(0));
+	set_p4d(p4dp, native_make_p4d(0));
 }
 
 static inline void set_pte_atomic(pte_t *ptep, pte_t pte)
@@ -504,12 +504,12 @@ static inline void set_pte_atomic(pte_t *ptep, pte_t pte)
 static inline void pte_clear(struct mm_struct *mm, unsigned long addr,
 			     pte_t *ptep)
 {
-	set_pte(ptep, __pte(0));
+	set_pte(ptep, native_make_pte(0));
 }
 
 static inline void pmd_clear(pmd_t *pmdp)
 {
-	set_pmd(pmdp, __pmd(0));
+	set_pmd(pmdp, native_make_pmd(0));
 }
 
 #define  __HAVE_ARCH_START_CONTEXT_SWITCH
-- 
2.26.2


WARNING: multiple messages have this Message-ID (diff)
From: Juergen Gross <jgross@suse.com>
To: xen-devel@lists.xenproject.org, x86@kernel.org,
	virtualization@lists.linux-foundation.org,
	linux-kernel@vger.kernel.org
Cc: Juergen Gross <jgross@suse.com>,
	"VMware, Inc." <pv-drivers@vmware.com>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH v4 6/6] x86/paravirt: avoid needless paravirt step clearing page table entries
Date: Sat, 15 Aug 2020 12:06:41 +0200	[thread overview]
Message-ID: <20200815100641.26362-7-jgross@suse.com> (raw)
In-Reply-To: <20200815100641.26362-1-jgross@suse.com>

pte_clear() et al are based on tw0 paravirt steps today: one step to
create a page table entry with all zeroes, and one step to write this
entry value.

Drop the first step as it is completely useless.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 arch/x86/include/asm/paravirt.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index f0464b88ea1e..d25cc6830e89 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -448,7 +448,7 @@ static inline pudval_t pud_val(pud_t pud)
 
 static inline void pud_clear(pud_t *pudp)
 {
-	set_pud(pudp, __pud(0));
+	set_pud(pudp, native_make_pud(0));
 }
 
 static inline void set_p4d(p4d_t *p4dp, p4d_t p4d)
@@ -485,15 +485,15 @@ static inline void __set_pgd(pgd_t *pgdp, pgd_t pgd)
 } while (0)
 
 #define pgd_clear(pgdp) do {						\
-	if (pgtable_l5_enabled())						\
-		set_pgd(pgdp, __pgd(0));				\
+	if (pgtable_l5_enabled())					\
+		set_pgd(pgdp, native_make_pgd(0));			\
 } while (0)
 
 #endif  /* CONFIG_PGTABLE_LEVELS == 5 */
 
 static inline void p4d_clear(p4d_t *p4dp)
 {
-	set_p4d(p4dp, __p4d(0));
+	set_p4d(p4dp, native_make_p4d(0));
 }
 
 static inline void set_pte_atomic(pte_t *ptep, pte_t pte)
@@ -504,12 +504,12 @@ static inline void set_pte_atomic(pte_t *ptep, pte_t pte)
 static inline void pte_clear(struct mm_struct *mm, unsigned long addr,
 			     pte_t *ptep)
 {
-	set_pte(ptep, __pte(0));
+	set_pte(ptep, native_make_pte(0));
 }
 
 static inline void pmd_clear(pmd_t *pmdp)
 {
-	set_pmd(pmdp, __pmd(0));
+	set_pmd(pmdp, native_make_pmd(0));
 }
 
 #define  __HAVE_ARCH_START_CONTEXT_SWITCH
-- 
2.26.2

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  parent reply	other threads:[~2020-08-15 21:44 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-15 10:06 [PATCH v4 0/6] x86/paravirt: cleanup after 32-bit PV removal Juergen Gross
2020-08-15 10:06 ` Juergen Gross
2020-08-15 10:06 ` [PATCH v4 1/6] x86/paravirt: remove 32-bit support from PARAVIRT_XXL Juergen Gross
2020-08-15 10:06   ` Juergen Gross
2020-08-15 15:46   ` [tip: x86/paravirt] x86/paravirt: Remove 32-bit support from CONFIG_PARAVIRT_XXL tip-bot2 for Juergen Gross
2020-08-16 18:37   ` [PATCH v4 1/6] x86/paravirt: remove 32-bit support from PARAVIRT_XXL boris.ostrovsky
2020-08-16 18:37     ` boris.ostrovsky
2020-08-15 10:06 ` [PATCH v4 2/6] x86/paravirt: cleanup paravirt macros Juergen Gross
2020-08-15 10:06   ` Juergen Gross
2020-08-15 15:46   ` [tip: x86/paravirt] x86/paravirt: Clean up " tip-bot2 for Juergen Gross
2020-08-15 10:06 ` [PATCH v4 3/6] x86/paravirt: use CONFIG_PARAVIRT_XXL instead of CONFIG_PARAVIRT Juergen Gross
2020-08-15 15:46   ` [tip: x86/paravirt] x86/paravirt: Use " tip-bot2 for Juergen Gross
2020-08-15 10:06 ` [PATCH v4 4/6] x86/entry/32: revert "Fix XEN_PV build dependency" Juergen Gross
2020-08-15 15:46   ` [tip: x86/paravirt] x86/entry/32: Simplify CONFIG_XEN_PV build dependency tip-bot2 for Juergen Gross
2020-08-15 10:06 ` [PATCH v4 5/6] x86/paravirt: remove set_pte_at pv-op Juergen Gross
2020-08-15 10:06   ` Juergen Gross
2020-08-15 15:46   ` [tip: x86/paravirt] x86/paravirt: Remove set_pte_at() pv-op tip-bot2 for Juergen Gross
2020-08-16 18:44   ` [PATCH v4 5/6] x86/paravirt: remove set_pte_at pv-op boris.ostrovsky
2020-08-16 18:44     ` boris.ostrovsky
2020-08-15 10:06 ` Juergen Gross [this message]
2020-08-15 10:06   ` [PATCH v4 6/6] x86/paravirt: avoid needless paravirt step clearing page table entries Juergen Gross
2020-08-15 15:46   ` [tip: x86/paravirt] x86/paravirt: Avoid " tip-bot2 for Juergen Gross

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