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From: Keqian Zhu <zhukeqian1@huawei.com>
To: <linux-kernel@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<kvmarm@lists.cs.columbia.edu>, <kvm@vger.kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Sean Christopherson <sean.j.christopherson@intel.com>,
	liangpeng10@huawei.com, Alexios Zavras <alexios.zavras@intel.com>,
	Mark Brown <broonie@kernel.org>, Marc Zyngier <maz@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Will Deacon <will@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: [PATCH 03/12] KVM: arm64: Report hardware dirty status of stage2 PTE if coverred
Date: Tue, 16 Jun 2020 17:35:44 +0800	[thread overview]
Message-ID: <20200616093553.27512-4-zhukeqian1@huawei.com> (raw)
In-Reply-To: <20200616093553.27512-1-zhukeqian1@huawei.com>

kvm_set_pte is called to replace a target PTE with a desired one.
We always do this without changing the desired one, but if dirty
status set by hardware is coverred, let caller know it.

Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
---
 arch/arm64/kvm/mmu.c | 36 +++++++++++++++++++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 5ad87bce23c0..27407153121b 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -194,11 +194,45 @@ static void clear_stage2_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr
 	put_page(virt_to_page(pmd));
 }
 
-static inline void kvm_set_pte(pte_t *ptep, pte_t new_pte)
+#ifdef CONFIG_ARM64_HW_AFDBM
+/**
+ * @ret: true if dirty status set by hardware is coverred.
+ */
+static bool kvm_set_pte(pte_t *ptep, pte_t new_pte)
+{
+	pteval_t old_pteval, new_pteval, pteval;
+	bool old_logging, new_no_write;
+
+	old_logging = kvm_hw_dbm_enabled() && !pte_none(*ptep) &&
+		      kvm_s2pte_dbm(ptep);
+	new_no_write = pte_none(new_pte) || kvm_s2pte_readonly(&new_pte);
+
+	if (!old_logging || !new_no_write) {
+		WRITE_ONCE(*ptep, new_pte);
+		dsb(ishst);
+		return false;
+	}
+
+	new_pteval = pte_val(new_pte);
+	pteval = READ_ONCE(pte_val(*ptep));
+	do {
+		old_pteval = pteval;
+		pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, new_pteval);
+	} while (pteval != old_pteval);
+
+	return !kvm_s2pte_readonly(&__pte(pteval));
+}
+#else
+/**
+ * @ret: true if dirty status set by hardware is coverred.
+ */
+static inline bool kvm_set_pte(pte_t *ptep, pte_t new_pte)
 {
 	WRITE_ONCE(*ptep, new_pte);
 	dsb(ishst);
+	return false;
 }
+#endif /* CONFIG_ARM64_HW_AFDBM */
 
 static inline void kvm_set_pmd(pmd_t *pmdp, pmd_t new_pmd)
 {
-- 
2.19.1

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  parent reply	other threads:[~2020-06-16  9:36 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-16  9:35 [PATCH 00/12] KVM: arm64: Support stage2 hardware DBM Keqian Zhu
2020-06-16  9:35 ` [PATCH 01/12] KVM: arm64: Add some basic functions to support hw DBM Keqian Zhu
2020-06-16  9:35 ` [PATCH 02/12] KVM: arm64: Modify stage2 young mechanism " Keqian Zhu
2020-06-16  9:35 ` Keqian Zhu [this message]
2020-07-01 11:28   ` [PATCH 03/12] KVM: arm64: Report hardware dirty status of stage2 PTE if coverred Steven Price
2020-07-02 11:28     ` zhukeqian
2020-06-16  9:35 ` [PATCH 04/12] KVM: arm64: Support clear DBM bit for PTEs Keqian Zhu
2020-06-16  9:35 ` [PATCH 05/12] KVM: arm64: Add KVM_CAP_ARM_HW_DIRTY_LOG capability Keqian Zhu
2020-06-16  9:35 ` [PATCH 06/12] KVM: arm64: Set DBM bit of PTEs during write protecting Keqian Zhu
2020-06-16  9:35 ` [PATCH 07/12] KVM: arm64: Scan PTEs to sync dirty log Keqian Zhu
2020-06-16  9:35 ` [PATCH 08/12] KVM: Omit dirty log sync in log clear if initially all set Keqian Zhu
2020-06-16  9:35 ` [PATCH 09/12] KVM: arm64: Steply write protect page table by mask bit Keqian Zhu
2020-06-16  9:35 ` [PATCH 10/12] KVM: arm64: Save stage2 PTE dirty status if it is coverred Keqian Zhu
2020-06-16  9:35 ` [PATCH 11/12] KVM: arm64: Support disable hw dirty log after enable Keqian Zhu
2020-06-16  9:35 ` [PATCH 12/12] KVM: arm64: Enable stage2 hardware DBM Keqian Zhu
2020-06-18  4:13 ` [PATCH 00/12] KVM: arm64: Support " zhukeqian

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