From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
"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>,
Arnd Bergmann <arnd@arndb.de>
Cc: Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-hyperv@vger.kernel.org,
linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
Ajay Garg <ajaygargnsit@gmail.com>
Subject: [PATCH v3 8/8] KVM: x86: Add checks for reserved-to-zero Hyper-V hypercall fields
Date: Tue, 7 Dec 2021 22:09:26 +0000 [thread overview]
Message-ID: <20211207220926.718794-9-seanjc@google.com> (raw)
In-Reply-To: <20211207220926.718794-1-seanjc@google.com>
Add checks for the three fields in Hyper-V's hypercall params that must
be zero. Per the TLFS, HV_STATUS_INVALID_HYPERCALL_INPUT is returned if
"A reserved bit in the specified hypercall input value is non-zero."
Note, some versions of the TLFS have an off-by-one bug for the last
reserved field, and define it as being bits 64:60. See
https://github.com/MicrosoftDocs/Virtualization-Documentation/pull/1682.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/hyperv.c | 5 +++++
include/asm-generic/hyperv-tlfs.h | 6 ++++++
2 files changed, 11 insertions(+)
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 522ccd2f0db4..3be59f13b467 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -2237,6 +2237,11 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
goto hypercall_complete;
}
+ if (unlikely(hc.param & HV_HYPERCALL_RSVD_MASK)) {
+ ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
+ goto hypercall_complete;
+ }
+
if (hc.fast && is_xmm_fast_hypercall(&hc)) {
if (unlikely(hv_vcpu->enforce_cpuid &&
!(hv_vcpu->cpuid_cache.features_edx &
diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
index 8a04c8fba598..2354378eef4c 100644
--- a/include/asm-generic/hyperv-tlfs.h
+++ b/include/asm-generic/hyperv-tlfs.h
@@ -184,11 +184,17 @@ enum HV_GENERIC_SET_FORMAT {
#define HV_HYPERCALL_FAST_BIT BIT(16)
#define HV_HYPERCALL_VARHEAD_OFFSET 17
#define HV_HYPERCALL_VARHEAD_MASK GENMASK_ULL(26, 17)
+#define HV_HYPERCALL_RSVD0_MASK GENMASK_ULL(31, 27)
#define HV_HYPERCALL_REP_COMP_OFFSET 32
#define HV_HYPERCALL_REP_COMP_1 BIT_ULL(32)
#define HV_HYPERCALL_REP_COMP_MASK GENMASK_ULL(43, 32)
+#define HV_HYPERCALL_RSVD1_MASK GENMASK_ULL(47, 44)
#define HV_HYPERCALL_REP_START_OFFSET 48
#define HV_HYPERCALL_REP_START_MASK GENMASK_ULL(59, 48)
+#define HV_HYPERCALL_RSVD2_MASK GENMASK_ULL(63, 60)
+#define HV_HYPERCALL_RSVD_MASK (HV_HYPERCALL_RSVD0_MASK | \
+ HV_HYPERCALL_RSVD1_MASK | \
+ HV_HYPERCALL_RSVD2_MASK)
/* hypercall status code */
#define HV_STATUS_SUCCESS 0
--
2.34.1.400.ga245620fadb-goog
next prev parent reply other threads:[~2021-12-07 22:09 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-07 22:09 [PATCH v3 0/8] KVM: x86: Hyper-V hypercall fix and cleanups Sean Christopherson
2021-12-07 22:09 ` [PATCH v3 1/8] KVM: x86: Ignore sparse banks size for an "all CPUs", non-sparse IPI req Sean Christopherson
2021-12-09 11:19 ` Paolo Bonzini
2021-12-07 22:09 ` [PATCH v3 2/8] KVM: x86: Get the number of Hyper-V sparse banks from the VARHEAD field Sean Christopherson
2021-12-07 22:09 ` [PATCH v3 3/8] KVM: x86: Refactor kvm_hv_flush_tlb() to reduce indentation Sean Christopherson
2021-12-07 22:09 ` [PATCH v3 4/8] KVM: x86: Add a helper to get the sparse VP_SET for IPIs and TLB flushes Sean Christopherson
2021-12-07 22:09 ` [PATCH v3 5/8] KVM: x86: Don't bother reading sparse banks that end up being ignored Sean Christopherson
2021-12-07 22:09 ` [PATCH v3 6/8] KVM: x86: Shove vp_bitmap handling down into sparse_set_to_vcpu_mask() Sean Christopherson
2021-12-07 22:09 ` [PATCH v3 7/8] KVM: x86: Reject fixeds-size Hyper-V hypercalls with non-zero "var_cnt" Sean Christopherson
2021-12-09 9:55 ` Vitaly Kuznetsov
2021-12-07 22:09 ` Sean Christopherson [this message]
2022-02-01 13:47 ` [PATCH v3 0/8] KVM: x86: Hyper-V hypercall fix and cleanups Paolo Bonzini
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