[PATCH v6 10/19] KVM: x86/xen: register shared_info page
From: David Woodhouse <dwmw2@infradead.org>
Date: 2021-02-03 15:02:48
Subsystem:
kernel virtual machine (kvm), kernel virtual machine for x86 (kvm/x86), kvm x86 xen (kvm/xen), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Paolo Bonzini, Sean Christopherson, David Woodhouse, Paul Durrant, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Joao Martins <redacted> Add KVM_XEN_ATTR_TYPE_SHARED_INFO to allow hypervisor to know where the guest's shared info page is. Signed-off-by: Joao Martins <redacted> Signed-off-by: David Woodhouse <redacted> --- arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/xen.c | 40 +++++++++++++++++++++++++++++---- include/uapi/linux/kvm.h | 4 ++++ 3 files changed, 42 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4ca6e060b578..07ae5887afa1 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h@@ -897,6 +897,8 @@ struct msr_bitmap_range { /* Xen emulation context */ struct kvm_xen { bool long_mode; + bool shinfo_set; + struct gfn_to_hva_cache shinfo_cache; }; enum kvm_irqchip_mode {
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 55da739267b1..924d4e853108 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c@@ -13,25 +13,49 @@ #include <linux/kvm_host.h> #include <trace/events/kvm.h> +#include <xen/interface/xen.h> #include "trace.h" DEFINE_STATIC_KEY_DEFERRED_FALSE(kvm_xen_enabled, HZ); +static int kvm_xen_shared_info_init(struct kvm *kvm, gfn_t gfn) +{ + int ret; + int idx = srcu_read_lock(&kvm->srcu); + + ret = kvm_gfn_to_hva_cache_init(kvm, &kvm->arch.xen.shinfo_cache, + gfn_to_gpa(gfn), PAGE_SIZE); + if (!ret) { + kvm->arch.xen.shinfo_set = true; + } + + srcu_read_unlock(&kvm->srcu, idx); + return ret; +} + int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) { int r = -ENOENT; + mutex_lock(&kvm->lock); + mutex_unlock(&kvm->lock); switch (data->type) { case KVM_XEN_ATTR_TYPE_LONG_MODE: - if (!IS_ENABLED(CONFIG_64BIT) && data->u.long_mode) - return -EINVAL; + if (!IS_ENABLED(CONFIG_64BIT) && data->u.long_mode) { + r = -EINVAL; + } else { + kvm->arch.xen.long_mode = !!data->u.long_mode; + r = 0; + } + break; - kvm->arch.xen.long_mode = !!data->u.long_mode; - r = 0; + case KVM_XEN_ATTR_TYPE_SHARED_INFO: + r = kvm_xen_shared_info_init(kvm, data->u.shared_info.gfn); break; + default: break; }
@@ -51,6 +75,14 @@ int kvm_xen_hvm_get_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data) data->u.long_mode = kvm->arch.xen.long_mode; r = 0; break; + + case KVM_XEN_ATTR_TYPE_SHARED_INFO: + if (kvm->arch.xen.shinfo_set) { + data->u.shared_info.gfn = gpa_to_gfn(kvm->arch.xen.shinfo_cache.gpa); + r = 0; + } + break; + default: break; }
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index e3ed21c333af..3c5b7ca7dce3 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h@@ -1593,11 +1593,15 @@ struct kvm_xen_hvm_attr { __u16 pad[3]; union { __u8 long_mode; + struct { + __u64 gfn; + } shared_info; __u64 pad[8]; } u; }; #define KVM_XEN_ATTR_TYPE_LONG_MODE 0x0 +#define KVM_XEN_ATTR_TYPE_SHARED_INFO 0x1 /* Secure Encrypted Virtualization command */ enum sev_cmd_id {
--
2.29.2