rebase patches on top of Ubuntu-5.3.0-41.33

[pve-kernel.git] / patches / kernel / 0010-x86-KVM-Make-sure-KVM_VCPU_FLUSH_TLB-flag-is-not-mis.patch

diff --git a/patches/kernel/0010-x86-KVM-Make-sure-KVM_VCPU_FLUSH_TLB-flag-is-not-mis.patch b/patches/kernel/0010-x86-KVM-Make-sure-KVM_VCPU_FLUSH_TLB-flag-is-not-mis.patch
deleted file mode 100644 (file)
index 506d50d..0000000
--- a/patches/kernel/0010-x86-KVM-Make-sure-KVM_VCPU_FLUSH_TLB-flag-is-not-mis.patch
+++ /dev/null
@@ -1,125 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
-Date: Fri, 31 Jan 2020 08:06:43 -0300
-Subject: [PATCH] x86/KVM: Make sure KVM_VCPU_FLUSH_TLB flag is not missed
-
-CVE-2019-3016
-CVE-2020-3016
-
-There is a potential race in record_steal_time() between setting
-host-local vcpu->arch.st.steal.preempted to zero (i.e. clearing
-KVM_VCPU_PREEMPTED) and propagating this value to the guest with
-kvm_write_guest_cached(). Between those two events the guest may
-still see KVM_VCPU_PREEMPTED in its copy of kvm_steal_time, set
-KVM_VCPU_FLUSH_TLB and assume that hypervisor will do the right
-thing. Which it won't.
-
-Instad of copying, we should map kvm_steal_time and that will
-guarantee atomicity of accesses to @preempted.
-
-This is part of CVE-2019-3016.
-
-Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
-Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
-Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
-Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
----
- arch/x86/kvm/x86.c | 49 +++++++++++++++++++++++++++-------------------
- 1 file changed, 29 insertions(+), 20 deletions(-)
-
-diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
-index cb18560b07bc..f63fa5846f08 100644
---- a/arch/x86/kvm/x86.c
-+++ b/arch/x86/kvm/x86.c
-@@ -2488,43 +2488,45 @@ static void kvm_vcpu_flush_tlb(struct kvm_vcpu *vcpu, bool invalidate_gpa)
- 
- static void record_steal_time(struct kvm_vcpu *vcpu)
- {
-+      struct kvm_host_map map;
-+      struct kvm_steal_time *st;
-+
-       if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
-               return;
- 
--      if (unlikely(kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
--              &vcpu->arch.st.steal, sizeof(struct kvm_steal_time))))
-+      /* -EAGAIN is returned in atomic context so we can just return. */
-+      if (kvm_map_gfn(vcpu, vcpu->arch.st.msr_val >> PAGE_SHIFT,
-+                      &map, &vcpu->arch.st.cache, false))
-               return;
- 
-+      st = map.hva +
-+              offset_in_page(vcpu->arch.st.msr_val & KVM_STEAL_VALID_BITS);
-+
-       /*
-        * Doing a TLB flush here, on the guest's behalf, can avoid
-        * expensive IPIs.
-        */
--      if (xchg(&vcpu->arch.st.steal.preempted, 0) & KVM_VCPU_FLUSH_TLB)
-+      if (xchg(&st->preempted, 0) & KVM_VCPU_FLUSH_TLB)
-               kvm_vcpu_flush_tlb(vcpu, false);
- 
--      if (vcpu->arch.st.steal.version & 1)
--              vcpu->arch.st.steal.version += 1;  /* first time write, random junk */
-+      vcpu->arch.st.steal.preempted = 0;
- 
--      vcpu->arch.st.steal.version += 1;
-+      if (st->version & 1)
-+              st->version += 1;  /* first time write, random junk */
- 
--      kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
--              &vcpu->arch.st.steal, sizeof(struct kvm_steal_time));
-+      st->version += 1;
- 
-       smp_wmb();
- 
--      vcpu->arch.st.steal.steal += current->sched_info.run_delay -
-+      st->steal += current->sched_info.run_delay -
-               vcpu->arch.st.last_steal;
-       vcpu->arch.st.last_steal = current->sched_info.run_delay;
- 
--      kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
--              &vcpu->arch.st.steal, sizeof(struct kvm_steal_time));
--
-       smp_wmb();
- 
--      vcpu->arch.st.steal.version += 1;
-+      st->version += 1;
- 
--      kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
--              &vcpu->arch.st.steal, sizeof(struct kvm_steal_time));
-+      kvm_unmap_gfn(vcpu, &map, &vcpu->arch.st.cache, true, false);
- }
- 
- int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
-@@ -3396,18 +3398,25 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
- 
- static void kvm_steal_time_set_preempted(struct kvm_vcpu *vcpu)
- {
-+      struct kvm_host_map map;
-+      struct kvm_steal_time *st;
-+
-       if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
-               return;
- 
-       if (vcpu->arch.st.steal.preempted)
-               return;
- 
--      vcpu->arch.st.steal.preempted = KVM_VCPU_PREEMPTED;
-+      if (kvm_map_gfn(vcpu, vcpu->arch.st.msr_val >> PAGE_SHIFT, &map,
-+                      &vcpu->arch.st.cache, true))
-+              return;
-+
-+      st = map.hva +
-+              offset_in_page(vcpu->arch.st.msr_val & KVM_STEAL_VALID_BITS);
-+
-+      st->preempted = vcpu->arch.st.steal.preempted = KVM_VCPU_PREEMPTED;
- 
--      kvm_write_guest_offset_cached(vcpu->kvm, &vcpu->arch.st.stime,
--                      &vcpu->arch.st.steal.preempted,
--                      offsetof(struct kvm_steal_time, preempted),
--                      sizeof(vcpu->arch.st.steal.preempted));
-+      kvm_unmap_gfn(vcpu, &map, &vcpu->arch.st.cache, true, true);
- }
- 
- void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)