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 v10 10/19] KVM: xen: (re-)initialize shared_info if guest (32/64-bit) mode is set
Date: Mon, 4 Dec 2023 14:43:25 +0000 [thread overview]
Message-ID: <20231204144334.910-11-paul@xen.org> (raw)
In-Reply-To: <20231204144334.910-1-paul@xen.org>
From: Paul Durrant <pdurrant@amazon.com>
If the shared_info PFN cache has already been initialized then the content
of the shared_info page needs to be (re-)initialized whenever the guest
mode is (re)set.
Setting the guest mode is either done explicitly by the VMM via the
KVM_XEN_ATTR_TYPE_LONG_MODE attribute, or implicitly when the guest writes
the MSR to set up the hypercall page.
Signed-off-by: Paul Durrant <pdurrant@amazon.com>
---
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
v10:
- New in this version.
---
arch/x86/kvm/xen.c | 36 +++++++++++++++++++++++++++++-------
1 file changed, 29 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 9351b32cfcba..3aa452a71890 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -623,10 +623,20 @@ int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
if (!IS_ENABLED(CONFIG_64BIT) && data->u.long_mode) {
r = -EINVAL;
} else {
+ bool lm = !!data->u.long_mode;
+
mutex_lock(&kvm->arch.xen.xen_lock);
- kvm->arch.xen.long_mode = !!data->u.long_mode;
+ if (kvm->arch.xen.long_mode != lm) {
+ kvm->arch.xen.long_mode = lm;
+
+ /*
+ * Re-initialize shared_info to put the wallclock in the
+ * correct place.
+ */
+ r = kvm->arch.xen.shinfo_cache.active ?
+ kvm_xen_shared_info_init(kvm) : 0;
+ }
mutex_unlock(&kvm->arch.xen.xen_lock);
- r = 0;
}
break;
@@ -648,9 +658,6 @@ int kvm_xen_hvm_set_attr(struct kvm *kvm, struct kvm_xen_hvm_attr *data)
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;
}
@@ -1101,9 +1108,24 @@ int kvm_xen_write_hypercall_page(struct kvm_vcpu *vcpu, u64 data)
u32 page_num = data & ~PAGE_MASK;
u64 page_addr = data & PAGE_MASK;
bool lm = is_long_mode(vcpu);
+ int r = 0;
+
+ mutex_lock(&kvm->arch.xen.xen_lock);
+ if (kvm->arch.xen.long_mode != lm) {
+ kvm->arch.xen.long_mode = lm;
+
+ /*
+ * Re-initialize shared_info to put the wallclock in the
+ * correct place.
+ */
+ if (kvm->arch.xen.shinfo_cache.active &&
+ kvm_xen_shared_info_init(kvm))
+ r = 1;
+ }
+ mutex_unlock(&kvm->arch.xen.xen_lock);
- /* Latch long_mode for shared_info pages etc. */
- vcpu->kvm->arch.xen.long_mode = lm;
+ if (r)
+ return r;
/*
* If Xen hypercall intercept is enabled, fill the hypercall
--
2.39.2
next prev parent reply other threads:[~2023-12-04 15:00 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-04 14:43 [PATCH v10 00/19] KVM: xen: update shared_info and vcpu_info handling Paul Durrant
2023-12-04 14:43 ` [PATCH v10 01/19] KVM: pfncache: Add a map helper function Paul Durrant
2023-12-04 14:43 ` [PATCH v10 02/19] KVM: pfncache: remove unnecessary exports Paul Durrant
2023-12-04 14:43 ` [PATCH v10 03/19] KVM: xen: mark guest pages dirty with the pfncache lock held Paul Durrant
2023-12-04 14:43 ` [PATCH v10 04/19] KVM: pfncache: add a mark-dirty helper Paul Durrant
2023-12-04 14:43 ` [PATCH v10 05/19] KVM: pfncache: remove KVM_GUEST_USES_PFN usage Paul Durrant
2023-12-04 14:43 ` [PATCH v10 06/19] KVM: pfncache: stop open-coding offset_in_page() Paul Durrant
2023-12-04 14:43 ` [PATCH v10 07/19] KVM: pfncache: include page offset in uhva and use it consistently Paul Durrant
2023-12-04 14:43 ` [PATCH v10 08/19] KVM: pfncache: allow a cache to be activated with a fixed (userspace) HVA Paul Durrant
2023-12-04 14:43 ` [PATCH v10 09/19] KVM: xen: separate initialization of shared_info cache and content Paul Durrant
2023-12-14 13:41 ` David Woodhouse
2023-12-14 14:00 ` Paul Durrant
2023-12-04 14:43 ` Paul Durrant [this message]
2023-12-14 13:44 ` [PATCH v10 10/19] KVM: xen: (re-)initialize shared_info if guest (32/64-bit) mode is set David Woodhouse
2023-12-04 14:43 ` [PATCH v10 11/19] KVM: xen: allow shared_info to be mapped by fixed HVA Paul Durrant
2023-12-04 14:43 ` [PATCH v10 12/19] KVM: xen: allow vcpu_info " Paul Durrant
2023-12-04 14:43 ` [PATCH v10 13/19] KVM: selftests / xen: map shared_info using HVA rather than GFN Paul Durrant
2023-12-04 14:43 ` [PATCH v10 14/19] KVM: selftests / xen: re-map vcpu_info using HVA rather than GPA Paul Durrant
2023-12-04 14:43 ` [PATCH v10 15/19] KVM: xen: advertize the KVM_XEN_HVM_CONFIG_SHARED_INFO_HVA capability Paul Durrant
2023-12-04 14:43 ` [PATCH v10 16/19] KVM: xen: split up kvm_xen_set_evtchn_fast() Paul Durrant
2023-12-14 14:00 ` David Woodhouse
2023-12-14 14:20 ` David Woodhouse
2023-12-04 14:43 ` [PATCH v10 17/19] KVM: xen: don't block on pfncache locks in kvm_xen_set_evtchn_fast() Paul Durrant
2023-12-14 14:03 ` David Woodhouse
2023-12-04 14:43 ` [PATCH v10 18/19] KVM: pfncache: check the need for invalidation under read lock first Paul Durrant
2023-12-14 14:08 ` David Woodhouse
2023-12-04 14:43 ` [PATCH v10 19/19] KVM: xen: allow vcpu_info content to be 'safely' copied Paul Durrant
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