linux-hyperv.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Sean Christopherson <seanjc@google.com>
To: "K. Y. Srinivasan" <kys@microsoft.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
	Sean Christopherson <seanjc@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: linux-hyperv@vger.kernel.org, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 3/4] KVM: SVM: Add a proper field for Hyper-V VMCB enlightenments
Date: Wed, 21 Sep 2022 20:16:06 +0000	[thread overview]
Message-ID: <20220921201607.3156750-4-seanjc@google.com> (raw)
In-Reply-To: <20220921201607.3156750-1-seanjc@google.com>

Add a union to provide hv_enlightenments side-by-side with the sw_reserved
bytes that Hyper-V's enlightenments overlay.  Casting sw_reserved
everywhere is messy, confusing, and unnecessarily unsafe.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/include/asm/svm.h                        |  7 ++++++-
 arch/x86/kvm/svm/nested.c                         |  9 ++++-----
 arch/x86/kvm/svm/svm.h                            |  5 ++++-
 arch/x86/kvm/svm/svm_onhyperv.c                   |  2 +-
 arch/x86/kvm/svm/svm_onhyperv.h                   | 15 +++++++--------
 tools/testing/selftests/kvm/include/x86_64/svm.h  |  5 ++++-
 .../selftests/kvm/x86_64/hyperv_svm_test.c        |  3 +--
 7 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 0361626841bc..6befed2b30a6 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -5,6 +5,8 @@
 #include <uapi/asm/svm.h>
 #include <uapi/asm/kvm.h>
 
+#include <asm/hyperv-tlfs.h>
+
 /*
  * 32-bit intercept words in the VMCB Control Area, starting
  * at Byte offset 000h.
@@ -161,7 +163,10 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
 	 * Offset 0x3e0, 32 bytes reserved
 	 * for use by hypervisor/software.
 	 */
-	u8 reserved_sw[32];
+	union {
+		struct hv_enlightenments hv_enlightenments;
+		u8 reserved_sw[32];
+	};
 };
 
 
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 76dcc8a3e849..a6a87d9743ce 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -201,8 +201,7 @@ void recalc_intercepts(struct vcpu_svm *svm)
  */
 static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
 {
-	struct hv_enlightenments *hve =
-		(struct hv_enlightenments *)svm->nested.ctl.reserved_sw;
+	struct hv_enlightenments *hve = &svm->nested.ctl.hv_enlightenments;
 	int i;
 
 	/*
@@ -391,8 +390,8 @@ void __nested_copy_vmcb_control_to_cache(struct kvm_vcpu *vcpu,
 	/* Hyper-V extensions (Enlightened VMCB) */
 	if (kvm_hv_hypercall_enabled(vcpu)) {
 		to->clean = from->clean;
-		memcpy(to->reserved_sw, from->reserved_sw,
-		       sizeof(struct hv_enlightenments));
+		memcpy(&to->hv_enlightenments, &from->hv_enlightenments,
+		       sizeof(to->hv_enlightenments));
 	}
 }
 
@@ -1485,7 +1484,7 @@ static void nested_copy_vmcb_cache_to_control(struct vmcb_control_area *dst,
 	dst->virt_ext              = from->virt_ext;
 	dst->pause_filter_count   = from->pause_filter_count;
 	dst->pause_filter_thresh  = from->pause_filter_thresh;
-	/* 'clean' and 'reserved_sw' are not changed by KVM */
+	/* 'clean' and 'hv_enlightenments' are not changed by KVM */
 }
 
 static int svm_get_nested_state(struct kvm_vcpu *vcpu,
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 6a7686bf6900..9eb2fc76732f 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -151,7 +151,10 @@ struct vmcb_ctrl_area_cached {
 	u64 nested_cr3;
 	u64 virt_ext;
 	u32 clean;
-	u8 reserved_sw[32];
+	union {
+		struct hv_enlightenments hv_enlightenments;
+		u8 reserved_sw[32];
+	};
 };
 
 struct svm_nested_state {
diff --git a/arch/x86/kvm/svm/svm_onhyperv.c b/arch/x86/kvm/svm/svm_onhyperv.c
index 8cdc62c74a96..5d4036611a37 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.c
+++ b/arch/x86/kvm/svm/svm_onhyperv.c
@@ -26,7 +26,7 @@ int svm_hv_enable_direct_tlbflush(struct kvm_vcpu *vcpu)
 	if (!*p_hv_pa_pg)
 		return -ENOMEM;
 
-	hve = (struct hv_enlightenments *)to_svm(vcpu)->vmcb->control.reserved_sw;
+	hve = &to_svm(vcpu)->vmcb->control.hv_enlightenments;
 
 	hve->partition_assist_page = __pa(*p_hv_pa_pg);
 	hve->hv_vm_id = (unsigned long)vcpu->kvm;
diff --git a/arch/x86/kvm/svm/svm_onhyperv.h b/arch/x86/kvm/svm/svm_onhyperv.h
index 8d02654ad6f8..c8f8045305be 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.h
+++ b/arch/x86/kvm/svm/svm_onhyperv.h
@@ -18,8 +18,10 @@ int svm_hv_enable_direct_tlbflush(struct kvm_vcpu *vcpu);
 
 static inline void svm_hv_init_vmcb(struct vmcb *vmcb)
 {
-	struct hv_enlightenments *hve =
-		(struct hv_enlightenments *)vmcb->control.reserved_sw;
+	struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments;
+
+	BUILD_BUG_ON(sizeof(vmcb->control.hv_enlightenments) !=
+		     sizeof(vmcb->control.reserved_sw));
 
 	if (npt_enabled &&
 	    ms_hyperv.nested_features & HV_X64_NESTED_ENLIGHTENED_TLB)
@@ -61,18 +63,15 @@ static inline void svm_hv_vmcb_dirty_nested_enlightenments(
 		struct kvm_vcpu *vcpu)
 {
 	struct vmcb *vmcb = to_svm(vcpu)->vmcb;
-	struct hv_enlightenments *hve =
-		(struct hv_enlightenments *)vmcb->control.reserved_sw;
+	struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments;
 
 	if (hve->hv_enlightenments_control.msr_bitmap)
 		vmcb_mark_dirty(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS);
 }
 
-static inline void svm_hv_update_vp_id(struct vmcb *vmcb,
-		struct kvm_vcpu *vcpu)
+static inline void svm_hv_update_vp_id(struct vmcb *vmcb, struct kvm_vcpu *vcpu)
 {
-	struct hv_enlightenments *hve =
-		(struct hv_enlightenments *)vmcb->control.reserved_sw;
+	struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments;
 	u32 vp_index = kvm_hv_get_vpindex(vcpu);
 
 	if (hve->hv_vp_id != vp_index) {
diff --git a/tools/testing/selftests/kvm/include/x86_64/svm.h b/tools/testing/selftests/kvm/include/x86_64/svm.h
index 10b9d0d4e0ec..0c32549c6b64 100644
--- a/tools/testing/selftests/kvm/include/x86_64/svm.h
+++ b/tools/testing/selftests/kvm/include/x86_64/svm.h
@@ -123,7 +123,10 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
 	 * Offset 0x3e0, 32 bytes reserved
 	 * for use by hypervisor/software.
 	 */
-	u8 reserved_sw[32];
+	union {
+		struct hv_enlightenments hv_enlightenments;
+		u8 reserved_sw[32];
+	};
 };
 
 
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
index b366b197759f..81b204ee509a 100644
--- a/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_svm_test.c
@@ -46,8 +46,7 @@ static void __attribute__((__flatten__)) guest_code(struct svm_test_data *svm)
 {
 	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
 	struct vmcb *vmcb = svm->vmcb;
-	struct hv_enlightenments *hve =
-		(struct hv_enlightenments *)vmcb->control.reserved_sw;
+	struct hv_enlightenments *hve = &vmcb->control.hv_enlightenments;
 
 	GUEST_SYNC(1);
 
-- 
2.37.3.968.ga6b4b080e4-goog


  parent reply	other threads:[~2022-09-21 20:16 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-21 20:16 [PATCH 0/4] x86/hyperv: KVM: VMCB enlightenment cleanups Sean Christopherson
2022-09-21 20:16 ` [PATCH 1/4] x86/hyperv: Move VMCB enlightenment definitions to hyperv-tlfs.h Sean Christopherson
2022-09-22 22:18   ` Michael Kelley (LINUX)
2022-09-22 22:22     ` Sean Christopherson
2022-09-27 10:11       ` Vitaly Kuznetsov
2022-09-21 20:16 ` [PATCH 2/4] KVM: selftests: Move "struct hv_enlightenments" to x86_64/svm.h Sean Christopherson
2022-09-21 20:16 ` Sean Christopherson [this message]
2022-09-21 20:16 ` [PATCH 4/4] x86/hyperv: KVM: Rename "hv_enlightenments" to "hv_vmcb_enlightenments" Sean Christopherson
2022-09-22 22:21   ` Michael Kelley (LINUX)

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220921201607.3156750-4-seanjc@google.com \
    --to=seanjc@google.com \
    --cc=decui@microsoft.com \
    --cc=haiyangz@microsoft.com \
    --cc=kvm@vger.kernel.org \
    --cc=kys@microsoft.com \
    --cc=linux-hyperv@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=pbonzini@redhat.com \
    --cc=sthemmin@microsoft.com \
    --cc=vkuznets@redhat.com \
    --cc=wei.liu@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).