| Message ID | 20220222154642.684285-4-vkuznets@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: x86: hyper-v: XMM fast hypercalls fixes | expand |
On Tue, Feb 22, 2022 at 04:46:41PM +0100, Vitaly Kuznetsov wrote: > CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe. > > > > When TLB flush hypercalls (HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}_EX are > issued in 'XMM fast' mode, the maximum number of allowed sparse_banks is > not 'HV_HYPERCALL_MAX_XMM_REGISTERS - 1' (5) but twice as many (10) as each > XMM register is 128 bit long and can hold two 64 bit long banks. > > Fixes: 5974565bc26d ("KVM: x86: kvm_hv_flush_tlb use inputs from XMM registers") > Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Indeed :) Reviewed-by: Siddharth Chandrasekaran <sidcha@amazon.de> Amazon Development Center Germany GmbH Krausenstr. 38 10117 Berlin Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B Sitz: Berlin Ust-ID: DE 289 237 879
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 714af3b94f31..6dda93bf98ae 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1820,7 +1820,8 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) if (!all_cpus) { if (hc->fast) { - if (sparse_banks_len > HV_HYPERCALL_MAX_XMM_REGISTERS - 1) + /* XMM0 is already consumed, each XMM holds two sparse banks. */ + if (sparse_banks_len > 2 * (HV_HYPERCALL_MAX_XMM_REGISTERS - 1)) return HV_STATUS_INVALID_HYPERCALL_INPUT; for (i = 0; i < sparse_banks_len; i += 2) { sparse_banks[i] = sse128_lo(hc->xmm[i / 2 + 1]);
When TLB flush hypercalls (HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}_EX are issued in 'XMM fast' mode, the maximum number of allowed sparse_banks is not 'HV_HYPERCALL_MAX_XMM_REGISTERS - 1' (5) but twice as many (10) as each XMM register is 128 bit long and can hold two 64 bit long banks. Fixes: 5974565bc26d ("KVM: x86: kvm_hv_flush_tlb use inputs from XMM registers") Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> --- arch/x86/kvm/hyperv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)