commit 05a4fbf680b806327a9c53525e9d8716dcdb55f3
parent 7f1da6e8d8fa76dfad3582ffb621e2f6683cabd7
Author: Louis Burda <quent.burda@gmail.com>
Date: Tue, 29 Nov 2022 15:26:37 +0100
Debug printf for detecting changes in shared SEV resources
Diffstat:
| M | patch.diff | | | 112 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------- |
1 file changed, 92 insertions(+), 20 deletions(-)
diff --git a/patch.diff b/patch.diff
@@ -467,7 +467,7 @@ index a4f6d10b0ef3..0c5aae1de162 100644
case SVM_EXIT_RDTSCP:
break;
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
-index cf0bf456d520..d915c8a3aff7 100644
+index cf0bf456d520..dee33c011251 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2,6 +2,10 @@
@@ -499,16 +499,99 @@ index cf0bf456d520..d915c8a3aff7 100644
return rc;
}
-@@ -2083,7 +2091,56 @@ static int smi_interception(struct kvm_vcpu *vcpu)
+@@ -2081,9 +2089,139 @@ static int smi_interception(struct kvm_vcpu *vcpu)
+ return 1;
+ }
++
++static inline int svm_map_ghcb(struct vcpu_svm *svm, struct kvm_host_map *map)
++{
++ struct vmcb_control_area *control = &svm->vmcb->control;
++ u64 gfn = gpa_to_gfn(control->ghcb_gpa);
++ struct kvm_vcpu *vcpu = &svm->vcpu;
++
++ if (kvm_vcpu_map(vcpu, gfn, map)) {
++ /* Unable to map GHCB from guest */
++ pr_err("error mapping GHCB GFN [%#llx] from guest\n", gfn);
++ return -EFAULT;
++ }
++
++ if (sev_post_map_gfn(vcpu->kvm, map->gfn, map->pfn)) {
++ kvm_vcpu_unmap(vcpu, map, false);
++ return -EBUSY;
++ }
++
++ return 0;
++}
++
++static inline void svm_unmap_ghcb(struct vcpu_svm *svm, struct kvm_host_map *map)
++{
++ struct kvm_vcpu *vcpu = &svm->vcpu;
++
++ kvm_vcpu_unmap(vcpu, map, true);
++ sev_post_unmap_gfn(vcpu->kvm, map->gfn, map->pfn);
++}
++
++static void hexdump(uint8_t *prev, uint8_t *cur, size_t len)
++{
++ size_t i;
++
++ for (i = 0; i < len; i++) {
++ if (cur[i] != prev[i])
++ printk(KERN_CONT "%02X ", cur[i]);
++ else
++ printk(KERN_CONT " ");
++ if ((i+1) % 16 == 0)
++ printk(KERN_CONT "\n");
++ }
++ printk(KERN_CONT "\n");
++}
++
static int intr_interception(struct kvm_vcpu *vcpu)
{
++ static struct vmcb_control_area prev_control;
++ //static struct ghcb prev_ghcb;
+ struct vcpu_svm *svm;
++ struct vmcb_control_area *control;
++ //struct kvm_host_map map;
++ //struct ghcb *ghcb;
+
++vcpu->stat.irq_exits;
+
+ if (cachepc_track_mode == CPC_TRACK_DATA_ACCESS && cachepc_single_step) {
+ svm = to_svm(vcpu);
++ control = &svm->vmcb->control;
++
++ CPC_WARN("RETINST %llu\n", cachepc_retinst);
++
++ // if (svm_map_ghcb(svm, &map)) {
++ // CPC_ERR("Mapping GHCB\n");
++ // return 1;
++ // }
++ // ghcb = map.hva;
++
++ // if (memcmp(&prev_ghcb, ghcb, sizeof(struct ghcb))) {
++ // pr_warn("GHCB DIFF HEXDUMP:\n");
++ // hexdump((void*)&prev_ghcb, (void *)ghcb,
++ // sizeof(struct ghcb));
++ // }
++
++ // memcpy(&prev_ghcb, ghcb, sizeof(struct ghcb));
++
++ // svm_unmap_ghcb(svm, &map);
++
++ if (memcmp(&prev_control, control, sizeof(struct vmcb_control_area))) {
++ pr_warn("VMCB DIFF HEXDUMP:\n");
++ hexdump((void*)&prev_control, (void *)control,
++ sizeof(struct vmcb_control_area));
++ }
++
++ memcpy(&prev_control, control, sizeof(struct vmcb_control_area));
++
++ if (cachepc_apic_timer < 1000) {
++ cachepc_apic_timer += 1;
++ return 1;
++ }
+
+ // if (svm->sev_es.vmsa->rip == cachepc_prev_rip) {
+ // cachepc_apic_timer += 1;
@@ -556,7 +639,7 @@ index cf0bf456d520..d915c8a3aff7 100644
return 1;
}
-@@ -3269,9 +3326,25 @@ static int svm_handle_invalid_exit(struct kvm_vcpu *vcpu, u64 exit_code)
+@@ -3269,9 +3407,25 @@ static int svm_handle_invalid_exit(struct kvm_vcpu *vcpu, u64 exit_code)
int svm_invoke_exit_handler(struct kvm_vcpu *vcpu, u64 exit_code)
{
@@ -582,30 +665,19 @@ index cf0bf456d520..d915c8a3aff7 100644
#ifdef CONFIG_RETPOLINE
if (exit_code == SVM_EXIT_MSR)
return msr_interception(vcpu);
-@@ -3788,14 +3861,58 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu)
+@@ -3787,15 +3941,46 @@ static fastpath_t svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu)
+ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
- unsigned long vmcb_pa = svm->current_vmcb->pa;
-+ int cpu, ret;
-+ u64 pfn;
+- unsigned long vmcb_pa = svm->current_vmcb->pa;
++ unsigned long vmcb_pa = svm->current_vmcb->pa;
++ int cpu;
guest_state_enter_irqoff();
if (sev_es_guest(vcpu->kvm)) {
+ if (cachepc_single_step && cachepc_apic_timer == 0) {
-+ pfn = __pa(svm->sev_es.vmsa) >> PAGE_SHIFT;
-+
+ cachepc_apic_timer = 100;
-+
-+ ret = rmp_make_shared(pfn, PG_LEVEL_4K);
-+ if (!ret) {
-+ CPC_DBG("VMSA %p\n", svm->sev_es.vmsa);
-+ CPC_DBG("RIP %llu\n", svm->sev_es.vmsa->rip);
-+ cachepc_prev_rip = svm->sev_es.vmsa->rip;
-+
-+ ret = rmp_make_private(pfn, -1, PG_LEVEL_4K, svm->asid, true);
-+ if (ret) CPC_ERR("Could not make VMSA private again\n");
-+ }
+ }
+
+ cpu = get_cpu();
@@ -641,7 +713,7 @@ index cf0bf456d520..d915c8a3aff7 100644
/*
* Use a single vmcb (vmcb01 because it's always valid) for
* context switching guest state via VMLOAD/VMSAVE, that way
-@@ -3806,7 +3923,15 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu)
+@@ -3806,7 +3991,15 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu)
__svm_vcpu_run(vmcb_pa, (unsigned long *)&vcpu->arch.regs);
vmsave(svm->vmcb01.pa);
