Re: [kvm-devel] [PATCH 4/8] X86: export information about NPT togeneric x86 code

From: Anthony Liguori
Date: Fri Jan 25 2008 - 16:38:13 EST


Joerg Roedel wrote:
The generic x86 code has to know if the specific implementation uses Nested
Paging. In the generic code Nested Paging is called Hardware Assisted Paging
(HAP) to avoid confusion with (future) HAP implementations of other vendors.
This patch exports the availability of HAP to the generic x86 code.

Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
arch/x86/kvm/svm.c | 7 +++++++
arch/x86/kvm/vmx.c | 7 +++++++
include/asm-x86/kvm_host.h | 2 ++
3 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 2e718ff..d0bfdd8 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1678,6 +1678,11 @@ static bool svm_cpu_has_accelerated_tpr(void)
return false;
}
+static bool svm_hap_enabled(void)
+{
+ return npt_enabled;
+}
+

To help with bisecting, you should probably return false here until the patch that actually implements NPT support. Otherwise, the 7th patch in this series breaks KVM for SVM.

Regards,

Anthony Liguori

static struct kvm_x86_ops svm_x86_ops = {
.cpu_has_kvm_support = has_svm,
.disabled_by_bios = is_disabled,
@@ -1734,6 +1739,8 @@ static struct kvm_x86_ops svm_x86_ops = {
.inject_pending_vectors = do_interrupt_requests,
.set_tss_addr = svm_set_tss_addr,
+
+ .hap_enabled = svm_hap_enabled,
};
static int __init svm_init(void)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 00a00e4..8feb775 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2631,6 +2631,11 @@ static void __init vmx_check_processor_compat(void *rtn)
}
}
+static bool vmx_hap_enabled(void)
+{
+ return false;
+}
+
static struct kvm_x86_ops vmx_x86_ops = {
.cpu_has_kvm_support = cpu_has_kvm_support,
.disabled_by_bios = vmx_disabled_by_bios,
@@ -2688,6 +2693,8 @@ static struct kvm_x86_ops vmx_x86_ops = {
.inject_pending_vectors = do_interrupt_requests,
.set_tss_addr = vmx_set_tss_addr,
+
+ .hap_enabled = vmx_hap_enabled,
};
static int __init vmx_init(void)
diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h
index 67ae307..45a9d05 100644
--- a/include/asm-x86/kvm_host.h
+++ b/include/asm-x86/kvm_host.h
@@ -392,6 +392,8 @@ struct kvm_x86_ops {
struct kvm_run *run);
int (*set_tss_addr)(struct kvm *kvm, unsigned int addr);
+
+ bool (*hap_enabled)(void);
};
extern struct kvm_x86_ops *kvm_x86_ops;

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