From: ajay <ajaygargnsit@xxxxxxxxx>
Issue :
=======
In "kvm_hv_flush_tlb" and "kvm_hv_send_ipi" methods, defining
"u64 sparse_banks[64]" inside the methods (on the stack), causes the
stack-segment-memory-allocation to go beyond 1024 bytes, thus raising the
warning/error which breaks the build.
Fix :
=====
Instead of defining "u64 sparse_banks [64]" inside the methods, we instead
define this array in the (only) client method "kvm_hv_hypercall", and then
pass the array (and its size) as additional arguments to the two methods.
Doing this, we do not exceed the 1024 bytes stack-segment-memory-allocation,
on any stack-segment of any method.
Signed-off-by: ajay <ajaygargnsit@xxxxxxxxx>
---
arch/x86/kvm/hyperv.c | 34 ++++++++++++++++++++++++----------
1 file changed, 24 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 232a86a6faaf..5340be93daa4 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1750,7 +1750,8 @@ struct kvm_hv_hcall {
sse128_t xmm[HV_HYPERCALL_MAX_XMM_REGISTERS];
};
-static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool ex)
+static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc,
+ bool ex, u64 *sparse_banks, u32 num_sparse_banks)
{
int i;
gpa_t gpa;
@@ -1762,10 +1763,11 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool
DECLARE_BITMAP(vcpu_bitmap, KVM_MAX_VCPUS);
unsigned long *vcpu_mask;
u64 valid_bank_mask;
- u64 sparse_banks[64];
int sparse_banks_len;
bool all_cpus;
+ memset(sparse_banks, 0, sizeof(u64) * num_sparse_banks);
+
if (!ex) {
if (hc->fast) {
flush.address_space = hc->ingpa;
@@ -1875,7 +1877,8 @@ static void kvm_send_ipi_to_many(struct kvm *kvm, u32 vector,
}
}
-static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool ex)
+static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc,
+ bool ex, u64 *sparse_banks, u32 num_sparse_banks)
{
struct kvm *kvm = vcpu->kvm;
struct hv_send_ipi_ex send_ipi_ex;
@@ -1884,11 +1887,12 @@ static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool
DECLARE_BITMAP(vcpu_bitmap, KVM_MAX_VCPUS);
unsigned long *vcpu_mask;
unsigned long valid_bank_mask;
- u64 sparse_banks[64];
int sparse_banks_len;
u32 vector;
bool all_cpus;
+ memset(sparse_banks, 0, sizeof(u64) * num_sparse_banks);
+
if (!ex) {
if (!hc->fast) {
if (unlikely(kvm_read_guest(kvm, hc->ingpa, &send_ipi,
@@ -2162,6 +2166,10 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
struct kvm_hv_hcall hc;
u64 ret = HV_STATUS_SUCCESS;
+#define NUM_SPARSE_BANKS 64
+
+ u64 sparse_banks[NUM_SPARSE_BANKS];
+
/*
* hypercall generates UD from non zero cpl and real mode
* per HYPER-V spec
@@ -2248,42 +2256,48 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
}
- ret = kvm_hv_flush_tlb(vcpu, &hc, false);
+ ret = kvm_hv_flush_tlb(vcpu, &hc, false,
+ sparse_banks, NUM_SPARSE_BANKS);
break;
case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE:
if (unlikely(hc.rep)) {
ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
}
- ret = kvm_hv_flush_tlb(vcpu, &hc, false);
+ ret = kvm_hv_flush_tlb(vcpu, &hc, false,
+ sparse_banks, NUM_SPARSE_BANKS);
break;
case HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX:
if (unlikely(!hc.rep_cnt || hc.rep_idx)) {
ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
}
- ret = kvm_hv_flush_tlb(vcpu, &hc, true);
+ ret = kvm_hv_flush_tlb(vcpu, &hc, true,
+ sparse_banks, NUM_SPARSE_BANKS);
break;
case HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX:
if (unlikely(hc.rep)) {
ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
}
- ret = kvm_hv_flush_tlb(vcpu, &hc, true);
+ ret = kvm_hv_flush_tlb(vcpu, &hc, true,
+ sparse_banks, NUM_SPARSE_BANKS);
break;
case HVCALL_SEND_IPI:
if (unlikely(hc.rep)) {
ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
}
- ret = kvm_hv_send_ipi(vcpu, &hc, false);
+ ret = kvm_hv_send_ipi(vcpu, &hc, false,
+ sparse_banks, NUM_SPARSE_BANKS);
break;
case HVCALL_SEND_IPI_EX:
if (unlikely(hc.fast || hc.rep)) {
ret = HV_STATUS_INVALID_HYPERCALL_INPUT;
break;
}
- ret = kvm_hv_send_ipi(vcpu, &hc, true);
+ ret = kvm_hv_send_ipi(vcpu, &hc, true,
+ sparse_banks, NUM_SPARSE_BANKS);
break;
case HVCALL_POST_DEBUG_DATA:
case HVCALL_RETRIEVE_DEBUG_DATA:
--
2.30.2
