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-rw-r--r--arch/x86/coco/sev/core.c255
1 files changed, 165 insertions, 90 deletions
diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c
index b0c1a7a57497..36beaac713c1 100644
--- a/arch/x86/coco/sev/core.c
+++ b/arch/x86/coco/sev/core.c
@@ -959,6 +959,102 @@ void snp_accept_memory(phys_addr_t start, phys_addr_t end)
set_pages_state(vaddr, npages, SNP_PAGE_STATE_PRIVATE);
}
+static int vmgexit_ap_control(u64 event, struct sev_es_save_area *vmsa, u32 apic_id)
+{
+ bool create = event != SVM_VMGEXIT_AP_DESTROY;
+ struct ghcb_state state;
+ unsigned long flags;
+ struct ghcb *ghcb;
+ int ret = 0;
+
+ local_irq_save(flags);
+
+ ghcb = __sev_get_ghcb(&state);
+
+ vc_ghcb_invalidate(ghcb);
+
+ if (create)
+ ghcb_set_rax(ghcb, vmsa->sev_features);
+
+ ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_AP_CREATION);
+ ghcb_set_sw_exit_info_1(ghcb,
+ ((u64)apic_id << 32) |
+ ((u64)snp_vmpl << 16) |
+ event);
+ ghcb_set_sw_exit_info_2(ghcb, __pa(vmsa));
+
+ sev_es_wr_ghcb_msr(__pa(ghcb));
+ VMGEXIT();
+
+ if (!ghcb_sw_exit_info_1_is_valid(ghcb) ||
+ lower_32_bits(ghcb->save.sw_exit_info_1)) {
+ pr_err("SNP AP %s error\n", (create ? "CREATE" : "DESTROY"));
+ ret = -EINVAL;
+ }
+
+ __sev_put_ghcb(&state);
+
+ local_irq_restore(flags);
+
+ return ret;
+}
+
+static int snp_set_vmsa(void *va, void *caa, int apic_id, bool make_vmsa)
+{
+ int ret;
+
+ if (snp_vmpl) {
+ struct svsm_call call = {};
+ unsigned long flags;
+
+ local_irq_save(flags);
+
+ call.caa = this_cpu_read(svsm_caa);
+ call.rcx = __pa(va);
+
+ if (make_vmsa) {
+ /* Protocol 0, Call ID 2 */
+ call.rax = SVSM_CORE_CALL(SVSM_CORE_CREATE_VCPU);
+ call.rdx = __pa(caa);
+ call.r8 = apic_id;
+ } else {
+ /* Protocol 0, Call ID 3 */
+ call.rax = SVSM_CORE_CALL(SVSM_CORE_DELETE_VCPU);
+ }
+
+ ret = svsm_perform_call_protocol(&call);
+
+ local_irq_restore(flags);
+ } else {
+ /*
+ * If the kernel runs at VMPL0, it can change the VMSA
+ * bit for a page using the RMPADJUST instruction.
+ * However, for the instruction to succeed it must
+ * target the permissions of a lesser privileged (higher
+ * numbered) VMPL level, so use VMPL1.
+ */
+ u64 attrs = 1;
+
+ if (make_vmsa)
+ attrs |= RMPADJUST_VMSA_PAGE_BIT;
+
+ ret = rmpadjust((unsigned long)va, RMP_PG_SIZE_4K, attrs);
+ }
+
+ return ret;
+}
+
+static void snp_cleanup_vmsa(struct sev_es_save_area *vmsa, int apic_id)
+{
+ int err;
+
+ err = snp_set_vmsa(vmsa, NULL, apic_id, false);
+ if (err)
+ pr_err("clear VMSA page failed (%u), leaking page\n", err);
+ else
+ free_page((unsigned long)vmsa);
+}
+
static void set_pte_enc(pte_t *kpte, int level, void *va)
{
struct pte_enc_desc d = {
@@ -1005,7 +1101,8 @@ static void unshare_all_memory(void)
data = per_cpu(runtime_data, cpu);
ghcb = (unsigned long)&data->ghcb_page;
- if (addr <= ghcb && ghcb <= addr + size) {
+ /* Handle the case of a huge page containing the GHCB page */
+ if (addr <= ghcb && ghcb < addr + size) {
skipped_addr = true;
break;
}
@@ -1055,11 +1152,70 @@ void snp_kexec_begin(void)
pr_warn("Failed to stop shared<->private conversions\n");
}
+/*
+ * Shutdown all APs except the one handling kexec/kdump and clearing
+ * the VMSA tag on AP's VMSA pages as they are not being used as
+ * VMSA page anymore.
+ */
+static void shutdown_all_aps(void)
+{
+ struct sev_es_save_area *vmsa;
+ int apic_id, this_cpu, cpu;
+
+ this_cpu = get_cpu();
+
+ /*
+ * APs are already in HLT loop when enc_kexec_finish() callback
+ * is invoked.
+ */
+ for_each_present_cpu(cpu) {
+ vmsa = per_cpu(sev_vmsa, cpu);
+
+ /*
+ * The BSP or offlined APs do not have guest allocated VMSA
+ * and there is no need to clear the VMSA tag for this page.
+ */
+ if (!vmsa)
+ continue;
+
+ /*
+ * Cannot clear the VMSA tag for the currently running vCPU.
+ */
+ if (this_cpu == cpu) {
+ unsigned long pa;
+ struct page *p;
+
+ pa = __pa(vmsa);
+ /*
+ * Mark the VMSA page of the running vCPU as offline
+ * so that is excluded and not touched by makedumpfile
+ * while generating vmcore during kdump.
+ */
+ p = pfn_to_online_page(pa >> PAGE_SHIFT);
+ if (p)
+ __SetPageOffline(p);
+ continue;
+ }
+
+ apic_id = cpuid_to_apicid[cpu];
+
+ /*
+ * Issue AP destroy to ensure AP gets kicked out of guest mode
+ * to allow using RMPADJUST to remove the VMSA tag on it's
+ * VMSA page.
+ */
+ vmgexit_ap_control(SVM_VMGEXIT_AP_DESTROY, vmsa, apic_id);
+ snp_cleanup_vmsa(vmsa, apic_id);
+ }
+
+ put_cpu();
+}
+
void snp_kexec_finish(void)
{
struct sev_es_runtime_data *data;
+ unsigned long size, addr;
unsigned int level, cpu;
- unsigned long size;
struct ghcb *ghcb;
pte_t *pte;
@@ -1069,6 +1225,8 @@ void snp_kexec_finish(void)
if (!IS_ENABLED(CONFIG_KEXEC_CORE))
return;
+ shutdown_all_aps();
+
unshare_all_memory();
/*
@@ -1085,54 +1243,11 @@ void snp_kexec_finish(void)
ghcb = &data->ghcb_page;
pte = lookup_address((unsigned long)ghcb, &level);
size = page_level_size(level);
- set_pte_enc(pte, level, (void *)ghcb);
- snp_set_memory_private((unsigned long)ghcb, (size / PAGE_SIZE));
- }
-}
-
-static int snp_set_vmsa(void *va, void *caa, int apic_id, bool make_vmsa)
-{
- int ret;
-
- if (snp_vmpl) {
- struct svsm_call call = {};
- unsigned long flags;
-
- local_irq_save(flags);
-
- call.caa = this_cpu_read(svsm_caa);
- call.rcx = __pa(va);
-
- if (make_vmsa) {
- /* Protocol 0, Call ID 2 */
- call.rax = SVSM_CORE_CALL(SVSM_CORE_CREATE_VCPU);
- call.rdx = __pa(caa);
- call.r8 = apic_id;
- } else {
- /* Protocol 0, Call ID 3 */
- call.rax = SVSM_CORE_CALL(SVSM_CORE_DELETE_VCPU);
- }
-
- ret = svsm_perform_call_protocol(&call);
-
- local_irq_restore(flags);
- } else {
- /*
- * If the kernel runs at VMPL0, it can change the VMSA
- * bit for a page using the RMPADJUST instruction.
- * However, for the instruction to succeed it must
- * target the permissions of a lesser privileged (higher
- * numbered) VMPL level, so use VMPL1.
- */
- u64 attrs = 1;
-
- if (make_vmsa)
- attrs |= RMPADJUST_VMSA_PAGE_BIT;
-
- ret = rmpadjust((unsigned long)va, RMP_PG_SIZE_4K, attrs);
+ /* Handle the case of a huge page containing the GHCB page */
+ addr = (unsigned long)ghcb & page_level_mask(level);
+ set_pte_enc(pte, level, (void *)addr);
+ snp_set_memory_private(addr, (size / PAGE_SIZE));
}
-
- return ret;
}
#define __ATTR_BASE (SVM_SELECTOR_P_MASK | SVM_SELECTOR_S_MASK)
@@ -1166,24 +1281,10 @@ static void *snp_alloc_vmsa_page(int cpu)
return page_address(p + 1);
}
-static void snp_cleanup_vmsa(struct sev_es_save_area *vmsa, int apic_id)
-{
- int err;
-
- err = snp_set_vmsa(vmsa, NULL, apic_id, false);
- if (err)
- pr_err("clear VMSA page failed (%u), leaking page\n", err);
- else
- free_page((unsigned long)vmsa);
-}
-
static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip)
{
struct sev_es_save_area *cur_vmsa, *vmsa;
- struct ghcb_state state;
struct svsm_ca *caa;
- unsigned long flags;
- struct ghcb *ghcb;
u8 sipi_vector;
int cpu, ret;
u64 cr4;
@@ -1297,33 +1398,7 @@ static int wakeup_cpu_via_vmgexit(u32 apic_id, unsigned long start_ip)
}
/* Issue VMGEXIT AP Creation NAE event */
- local_irq_save(flags);
-
- ghcb = __sev_get_ghcb(&state);
-
- vc_ghcb_invalidate(ghcb);
- ghcb_set_rax(ghcb, vmsa->sev_features);
- ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_AP_CREATION);
- ghcb_set_sw_exit_info_1(ghcb,
- ((u64)apic_id << 32) |
- ((u64)snp_vmpl << 16) |
- SVM_VMGEXIT_AP_CREATE);
- ghcb_set_sw_exit_info_2(ghcb, __pa(vmsa));
-
- sev_es_wr_ghcb_msr(__pa(ghcb));
- VMGEXIT();
-
- if (!ghcb_sw_exit_info_1_is_valid(ghcb) ||
- lower_32_bits(ghcb->save.sw_exit_info_1)) {
- pr_err("SNP AP Creation error\n");
- ret = -EINVAL;
- }
-
- __sev_put_ghcb(&state);
-
- local_irq_restore(flags);
-
- /* Perform cleanup if there was an error */
+ ret = vmgexit_ap_control(SVM_VMGEXIT_AP_CREATE, vmsa, apic_id);
if (ret) {
snp_cleanup_vmsa(vmsa, apic_id);
vmsa = NULL;
generated by cgit v1.2.3 (git 2.39.0) at 2025-05-22 23:42:19 +0300