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From: "Joerg Roedel" <joerg.roedel@amd.com>
To: "Avi Kivity" <avi@qumranet.com>
Cc: kvm-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org,
	"Joerg Roedel" <joerg.roedel@amd.com>
Subject: [PATCH 4/8] X86: export information about NPT to generic x86 code
Date: Thu,  7 Feb 2008 13:47:41 +0100	[thread overview]
Message-ID: <1202388465-8657-5-git-send-email-joerg.roedel@amd.com> (raw)
In-Reply-To: <1202388465-8657-1-git-send-email-joerg.roedel@amd.com>

The generic x86 code has to know if the specific implementation uses Nested
Paging. In the generic code Nested Paging is called Two Dimensional Paging
(TDP) to avoid confusion with (future) TDP implementations of other vendors.
This patch exports the availability of TDP to the generic x86 code.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
 arch/x86/kvm/mmu.c         |   15 +++++++++++++++
 arch/x86/kvm/svm.c         |    4 +++-
 include/asm-x86/kvm_host.h |    2 ++
 3 files changed, 20 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 635e70c..3477395 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -32,6 +32,15 @@
 #include <asm/cmpxchg.h>
 #include <asm/io.h>
 
+/*
+ * When setting this variable to true it enables Two-Dimensional-Paging
+ * where the hardware walks 2 page tables:
+ * 1. the guest-virtual to guest-physical
+ * 2. while doing 1. it walks guest-physical to host-physical
+ * If the hardware supports that we don't need to do shadow paging.
+ */
+static bool tdp_enabled = false;
+
 #undef MMU_DEBUG
 
 #undef AUDIT
@@ -1562,6 +1571,12 @@ out:
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
 
+void kvm_enable_tdp(void)
+{
+	tdp_enabled = true;
+}
+EXPORT_SYMBOL_GPL(kvm_enable_tdp);
+
 static void free_mmu_pages(struct kvm_vcpu *vcpu)
 {
 	struct kvm_mmu_page *sp;
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 8173ba6..f400499 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -423,8 +423,10 @@ static __init int svm_hardware_setup(void)
 		npt_enabled = false;
 	}
 
-	if (npt_enabled)
+	if (npt_enabled) {
 		printk(KERN_INFO "kvm: Nested Paging enabled\n");
+		kvm_enable_tdp();
+	}
 
 	return 0;
 
diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h
index 67ae307..7661da0 100644
--- a/include/asm-x86/kvm_host.h
+++ b/include/asm-x86/kvm_host.h
@@ -491,6 +491,8 @@ int kvm_fix_hypercall(struct kvm_vcpu *vcpu);
 
 int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t gva, u32 error_code);
 
+void kvm_enable_tdp(void);
+
 int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3);
 int complete_pio(struct kvm_vcpu *vcpu);
 
-- 
1.5.3.7




  parent reply	other threads:[~2008-02-07 12:50 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-07 12:47 KVM: add support for SVM Nested Paging Joerg Roedel
2008-02-07 12:47 ` [PATCH 1/8] SVM: move feature detection to hardware setup code Joerg Roedel
2008-02-07 12:47 ` [PATCH 2/8] SVM: add detection of Nested Paging feature Joerg Roedel
2008-02-07 12:47 ` [PATCH 3/8] SVM: add module parameter to disable Nested Paging Joerg Roedel
2008-02-07 12:47 ` Joerg Roedel [this message]
2008-02-07 12:47 ` [PATCH 5/8] MMU: make the __nonpaging_map function generic Joerg Roedel
2008-02-07 12:47 ` [PATCH 6/8] X86: export the load_pdptrs() function to modules Joerg Roedel
2008-02-07 12:47 ` [PATCH 7/8] MMU: add TDP support to the KVM MMU Joerg Roedel
2008-02-07 13:27   ` [kvm-devel] " Izik Eidus
2008-02-07 13:50     ` Joerg Roedel
2008-02-07 14:04       ` Izik Eidus
2008-02-07 12:47 ` [PATCH 8/8] SVM: add support for Nested Paging Joerg Roedel
2008-02-10 12:03 ` [kvm-devel] KVM: add support for SVM " Avi Kivity
  -- strict thread matches above, loose matches on Subject: below --
2008-01-25 20:53 [PATCH][RFC] SVM: Add Support for Nested Paging in AMD Fam16 CPUs Joerg Roedel
2008-01-25 20:53 ` [PATCH 4/8] X86: export information about NPT to generic x86 code Joerg Roedel

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