From: Paul Durrant <paul@xen.org>
To: Paolo Bonzini <pbonzini@redhat.com>,
Jonathan Corbet <corbet@lwn.net>,
Sean Christopherson <seanjc@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
David Woodhouse <dwmw2@infradead.org>,
Paul Durrant <paul@xen.org>, Shuah Khan <shuah@kernel.org>,
kvm@vger.kernel.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org
Subject: [PATCH v12 09/20] KVM: xen: separate initialization of shared_info cache and content
Date: Mon, 15 Jan 2024 12:56:56 +0000 [thread overview]
Message-ID: <20240115125707.1183-10-paul@xen.org> (raw)
In-Reply-To: <20240115125707.1183-1-paul@xen.org>
From: Paul Durrant <pdurrant@amazon.com>
A subsequent patch will allow shared_info to be initialized using either a
GPA or a user-space (i.e. VMM) HVA. To make that patch cleaner, separate
the initialization of the shared_info content from the activation of the
pfncache.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
---
Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: x86@kernel.org
v11:
- Fix accidental regression from commit 5d6d6a7d7e66a ("KVM: x86: Refine
calculation of guest wall clock to use a single TSC read").
v10:
- New in this version.
---
arch/x86/kvm/xen.c | 55 +++++++++++++++++++++++++++-------------------
1 file changed, 32 insertions(+), 23 deletions(-)
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index f9b1e494c430..df53fea73747 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -34,41 +34,32 @@ static bool kvm_xen_hcall_evtchn_send(struct kvm_vcpu *vcpu, u64 param, u64 *r);
DEFINE_STATIC_KEY_DEFERRED_FALSE(kvm_xen_enabled, HZ);
-static int kvm_xen_shared_info_init(struct kvm *kvm, gfn_t gfn)
+static int kvm_xen_shared_info_init(struct kvm *kvm)
{
struct gfn_to_pfn_cache *gpc = &kvm->arch.xen.shinfo_cache;
struct pvclock_wall_clock *wc;
- gpa_t gpa = gfn_to_gpa(gfn);
u32 *wc_sec_hi;
u32 wc_version;
u64 wall_nsec;
int ret = 0;
int idx = srcu_read_lock(&kvm->srcu);
- if (gfn == KVM_XEN_INVALID_GFN) {
- kvm_gpc_deactivate(gpc);
- goto out;
- }
+ read_lock_irq(&gpc->lock);
+ while (!kvm_gpc_check(gpc, PAGE_SIZE)) {
+ read_unlock_irq(&gpc->lock);
- do {
- ret = kvm_gpc_activate(gpc, gpa, PAGE_SIZE);
+ ret = kvm_gpc_refresh(gpc, PAGE_SIZE);
if (ret)
goto out;
- /*
- * This code mirrors kvm_write_wall_clock() except that it writes
- * directly through the pfn cache and doesn't mark the page dirty.
- */
- wall_nsec = kvm_get_wall_clock_epoch(kvm);
-
- /* It could be invalid again already, so we need to check */
read_lock_irq(&gpc->lock);
+ }
- if (gpc->valid)
- break;
-
- read_unlock_irq(&gpc->lock);
- } while (1);
+ /*
+ * This code mirrors kvm_write_wall_clock() except that it writes
+ * directly through the pfn cache and doesn't mark the page dirty.
+ */
+ wall_nsec = kvm_get_wall_clock_epoch(kvm);
/* Paranoia checks on the 32-bit struct layout */
BUILD_BUG_ON(offsetof(struct compat_shared_info, wc) != 0x900);
@@ -639,12 +630,30 @@ int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
}
break;
- case KVM_XEN_ATTR_TYPE_SHARED_INFO:
+ case KVM_XEN_ATTR_TYPE_SHARED_INFO: {
+ int idx;
+
mutex_lock(&kvm->arch.xen.xen_lock);
- r = kvm_xen_shared_info_init(kvm, data->u.shared_info.gfn);
+
+ idx = srcu_read_lock(&kvm->srcu);
+
+ if (data->u.shared_info.gfn == KVM_XEN_INVALID_GFN) {
+ kvm_gpc_deactivate(&kvm->arch.xen.shinfo_cache);
+ r = 0;
+ } else {
+ r = kvm_gpc_activate(&kvm->arch.xen.shinfo_cache,
+ gfn_to_gpa(data->u.shared_info.gfn),
+ PAGE_SIZE);
+ }
+
+ srcu_read_unlock(&kvm->srcu, idx);
+
+ if (!r && kvm->arch.xen.shinfo_cache.active)
+ r = kvm_xen_shared_info_init(kvm);
+
mutex_unlock(&kvm->arch.xen.xen_lock);
break;
-
+ }
case KVM_XEN_ATTR_TYPE_UPCALL_VECTOR:
if (data->u.vector && data->u.vector < 0x10)
r = -EINVAL;
--
2.39.2
next prev parent reply other threads:[~2024-01-15 12:58 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-15 12:56 [PATCH v12 00/20] KVM: xen: update shared_info and vcpu_info handling Paul Durrant
2024-01-15 12:56 ` [PATCH v12 01/20] KVM: pfncache: Add a map helper function Paul Durrant
2024-01-15 12:56 ` [PATCH v12 02/20] KVM: pfncache: remove unnecessary exports Paul Durrant
2024-01-15 12:56 ` [PATCH v12 03/20] KVM: xen: mark guest pages dirty with the pfncache lock held Paul Durrant
2024-02-07 3:17 ` Sean Christopherson
2024-02-07 3:26 ` David Woodhouse
2024-02-07 15:15 ` Sean Christopherson
2024-02-07 8:48 ` Paul Durrant
2024-01-15 12:56 ` [PATCH v12 04/20] KVM: pfncache: add a mark-dirty helper Paul Durrant
2024-02-07 3:20 ` Sean Christopherson
2024-02-07 8:47 ` Paul Durrant
2024-02-09 15:58 ` Sean Christopherson
2024-02-09 16:05 ` Paul Durrant
2024-01-15 12:56 ` [PATCH v12 05/20] KVM: pfncache: remove KVM_GUEST_USES_PFN usage Paul Durrant
2024-01-15 12:56 ` [PATCH v12 06/20] KVM: pfncache: stop open-coding offset_in_page() Paul Durrant
2024-01-15 12:56 ` [PATCH v12 07/20] KVM: pfncache: include page offset in uhva and use it consistently Paul Durrant
2024-01-15 12:56 ` [PATCH v12 08/20] KVM: pfncache: allow a cache to be activated with a fixed (userspace) HVA Paul Durrant
2024-02-07 4:03 ` Sean Christopherson
2024-02-07 4:13 ` David Woodhouse
2024-02-14 16:01 ` Sean Christopherson
2024-02-14 16:09 ` Paul Durrant
2024-02-14 15:21 ` Paul Durrant
2024-02-14 16:20 ` Sean Christopherson
2024-02-14 16:33 ` Paul Durrant
2024-01-15 12:56 ` Paul Durrant [this message]
2024-01-15 12:56 ` [PATCH v12 10/20] KVM: xen: re-initialize shared_info if guest (32/64-bit) mode is set Paul Durrant
2024-01-15 12:56 ` [PATCH v12 11/20] KVM: xen: allow shared_info to be mapped by fixed HVA Paul Durrant
2024-02-07 4:10 ` Sean Christopherson
2024-02-07 8:53 ` Paul Durrant
2024-02-08 8:52 ` Paul Durrant
2024-02-08 16:48 ` Sean Christopherson
2024-02-08 16:51 ` Paul Durrant
2024-02-08 17:26 ` David Woodhouse
2024-02-09 16:01 ` Sean Christopherson
2024-01-15 12:56 ` [PATCH v12 12/20] KVM: xen: allow vcpu_info " Paul Durrant
2024-01-15 12:57 ` [PATCH v12 13/20] KVM: selftests / xen: map shared_info using HVA rather than GFN Paul Durrant
2024-02-07 4:14 ` Sean Christopherson
2024-02-07 8:54 ` Paul Durrant
2024-02-07 14:58 ` Sean Christopherson
2024-01-15 12:57 ` [PATCH v12 14/20] KVM: selftests / xen: re-map vcpu_info using HVA rather than GPA Paul Durrant
2024-01-15 12:57 ` [PATCH v12 15/20] KVM: xen: advertize the KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA capability Paul Durrant
2024-01-15 12:57 ` [PATCH v12 16/20] KVM: xen: split up kvm_xen_set_evtchn_fast() Paul Durrant
2024-01-15 12:57 ` [PATCH v12 17/20] KVM: xen: don't block on pfncache locks in kvm_xen_set_evtchn_fast() Paul Durrant
2024-02-07 4:17 ` Sean Christopherson
2024-02-07 4:21 ` David Woodhouse
2024-01-15 12:57 ` [PATCH v12 18/20] KVM: pfncache: check the need for invalidation under read lock first Paul Durrant
2024-02-07 4:22 ` Sean Christopherson
2024-02-07 4:27 ` David Woodhouse
2024-02-07 4:47 ` Sean Christopherson
2024-02-07 4:59 ` David Woodhouse
2024-02-07 15:10 ` Sean Christopherson
2024-01-15 12:57 ` [PATCH v12 19/20] KVM: xen: allow vcpu_info content to be 'safely' copied Paul Durrant
2024-01-15 12:57 ` [PATCH v12 20/20] KVM: pfncache: rework __kvm_gpc_refresh() to fix locking issues Paul Durrant
2024-01-25 15:03 ` [PATCH v12 00/20] KVM: xen: update shared_info and vcpu_info handling Paul Durrant
2024-01-25 20:07 ` David Woodhouse
2024-01-26 1:19 ` Sean Christopherson
2024-02-02 17:37 ` Paul Durrant
2024-02-02 22:03 ` Sean Christopherson
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