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Diffstat (limited to 'arch/powerpc/kvm/book3s_hv_p9_entry.c')
-rw-r--r--arch/powerpc/kvm/book3s_hv_p9_entry.c508
1 files changed, 508 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c
new file mode 100644
index 000000000000..83f592eadcd2
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c
@@ -0,0 +1,508 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/kernel.h>
+#include <linux/kvm_host.h>
+#include <asm/asm-prototypes.h>
+#include <asm/dbell.h>
+#include <asm/kvm_ppc.h>
+#include <asm/ppc-opcode.h>
+
+#ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING
+static void __start_timing(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator *next)
+{
+ struct kvmppc_vcore *vc = vcpu->arch.vcore;
+ u64 tb = mftb() - vc->tb_offset_applied;
+
+ vcpu->arch.cur_activity = next;
+ vcpu->arch.cur_tb_start = tb;
+}
+
+static void __accumulate_time(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator *next)
+{
+ struct kvmppc_vcore *vc = vcpu->arch.vcore;
+ struct kvmhv_tb_accumulator *curr;
+ u64 tb = mftb() - vc->tb_offset_applied;
+ u64 prev_tb;
+ u64 delta;
+ u64 seq;
+
+ curr = vcpu->arch.cur_activity;
+ vcpu->arch.cur_activity = next;
+ prev_tb = vcpu->arch.cur_tb_start;
+ vcpu->arch.cur_tb_start = tb;
+
+ if (!curr)
+ return;
+
+ delta = tb - prev_tb;
+
+ seq = curr->seqcount;
+ curr->seqcount = seq + 1;
+ smp_wmb();
+ curr->tb_total += delta;
+ if (seq == 0 || delta < curr->tb_min)
+ curr->tb_min = delta;
+ if (delta > curr->tb_max)
+ curr->tb_max = delta;
+ smp_wmb();
+ curr->seqcount = seq + 2;
+}
+
+#define start_timing(vcpu, next) __start_timing(vcpu, next)
+#define end_timing(vcpu) __start_timing(vcpu, NULL)
+#define accumulate_time(vcpu, next) __accumulate_time(vcpu, next)
+#else
+#define start_timing(vcpu, next) do {} while (0)
+#define end_timing(vcpu) do {} while (0)
+#define accumulate_time(vcpu, next) do {} while (0)
+#endif
+
+static inline void mfslb(unsigned int idx, u64 *slbee, u64 *slbev)
+{
+ asm volatile("slbmfev %0,%1" : "=r" (*slbev) : "r" (idx));
+ asm volatile("slbmfee %0,%1" : "=r" (*slbee) : "r" (idx));
+}
+
+static inline void mtslb(u64 slbee, u64 slbev)
+{
+ asm volatile("slbmte %0,%1" :: "r" (slbev), "r" (slbee));
+}
+
+static inline void clear_slb_entry(unsigned int idx)
+{
+ mtslb(idx, 0);
+}
+
+static inline void slb_clear_invalidate_partition(void)
+{
+ clear_slb_entry(0);
+ asm volatile(PPC_SLBIA(6));
+}
+
+/*
+ * Malicious or buggy radix guests may have inserted SLB entries
+ * (only 0..3 because radix always runs with UPRT=1), so these must
+ * be cleared here to avoid side-channels. slbmte is used rather
+ * than slbia, as it won't clear cached translations.
+ */
+static void radix_clear_slb(void)
+{
+ int i;
+
+ for (i = 0; i < 4; i++)
+ clear_slb_entry(i);
+}
+
+static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
+{
+ struct kvm_nested_guest *nested = vcpu->arch.nested;
+ u32 lpid;
+
+ lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
+
+ /*
+ * All the isync()s are overkill but trivially follow the ISA
+ * requirements. Some can likely be replaced with justification
+ * comment for why they are not needed.
+ */
+ isync();
+ mtspr(SPRN_LPID, lpid);
+ isync();
+ mtspr(SPRN_LPCR, lpcr);
+ isync();
+ mtspr(SPRN_PID, vcpu->arch.pid);
+ isync();
+}
+
+static void switch_mmu_to_guest_hpt(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
+{
+ u32 lpid;
+ int i;
+
+ lpid = kvm->arch.lpid;
+
+ mtspr(SPRN_LPID, lpid);
+ mtspr(SPRN_LPCR, lpcr);
+ mtspr(SPRN_PID, vcpu->arch.pid);
+
+ for (i = 0; i < vcpu->arch.slb_max; i++)
+ mtslb(vcpu->arch.slb[i].orige, vcpu->arch.slb[i].origv);
+
+ isync();
+}
+
+static void switch_mmu_to_host(struct kvm *kvm, u32 pid)
+{
+ isync();
+ mtspr(SPRN_PID, pid);
+ isync();
+ mtspr(SPRN_LPID, kvm->arch.host_lpid);
+ isync();
+ mtspr(SPRN_LPCR, kvm->arch.host_lpcr);
+ isync();
+
+ if (!radix_enabled())
+ slb_restore_bolted_realmode();
+}
+
+static void save_clear_host_mmu(struct kvm *kvm)
+{
+ if (!radix_enabled()) {
+ /*
+ * Hash host could save and restore host SLB entries to
+ * reduce SLB fault overheads of VM exits, but for now the
+ * existing code clears all entries and restores just the
+ * bolted ones when switching back to host.
+ */
+ slb_clear_invalidate_partition();
+ }
+}
+
+static void save_clear_guest_mmu(struct kvm *kvm, struct kvm_vcpu *vcpu)
+{
+ if (kvm_is_radix(kvm)) {
+ radix_clear_slb();
+ } else {
+ int i;
+ int nr = 0;
+
+ /*
+ * This must run before switching to host (radix host can't
+ * access all SLBs).
+ */
+ for (i = 0; i < vcpu->arch.slb_nr; i++) {
+ u64 slbee, slbev;
+ mfslb(i, &slbee, &slbev);
+ if (slbee & SLB_ESID_V) {
+ vcpu->arch.slb[nr].orige = slbee | i;
+ vcpu->arch.slb[nr].origv = slbev;
+ nr++;
+ }
+ }
+ vcpu->arch.slb_max = nr;
+ slb_clear_invalidate_partition();
+ }
+}
+
+int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr)
+{
+ struct kvm *kvm = vcpu->kvm;
+ struct kvm_nested_guest *nested = vcpu->arch.nested;
+ struct kvmppc_vcore *vc = vcpu->arch.vcore;
+ s64 hdec;
+ u64 tb, purr, spurr;
+ u64 *exsave;
+ bool ri_set;
+ int trap;
+ unsigned long msr;
+ unsigned long host_hfscr;
+ unsigned long host_ciabr;
+ unsigned long host_dawr0;
+ unsigned long host_dawrx0;
+ unsigned long host_psscr;
+ unsigned long host_pidr;
+ unsigned long host_dawr1;
+ unsigned long host_dawrx1;
+
+ hdec = time_limit - mftb();
+ if (hdec < 0)
+ return BOOK3S_INTERRUPT_HV_DECREMENTER;
+
+ WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_HV);
+ WARN_ON_ONCE(!(vcpu->arch.shregs.msr & MSR_ME));
+
+ start_timing(vcpu, &vcpu->arch.rm_entry);
+
+ vcpu->arch.ceded = 0;
+
+ if (vc->tb_offset) {
+ u64 new_tb = mftb() + vc->tb_offset;
+ mtspr(SPRN_TBU40, new_tb);
+ tb = mftb();
+ if ((tb & 0xffffff) < (new_tb & 0xffffff))
+ mtspr(SPRN_TBU40, new_tb + 0x1000000);
+ vc->tb_offset_applied = vc->tb_offset;
+ }
+
+ msr = mfmsr();
+
+ host_hfscr = mfspr(SPRN_HFSCR);
+ host_ciabr = mfspr(SPRN_CIABR);
+ host_dawr0 = mfspr(SPRN_DAWR0);
+ host_dawrx0 = mfspr(SPRN_DAWRX0);
+ host_psscr = mfspr(SPRN_PSSCR);
+ host_pidr = mfspr(SPRN_PID);
+ if (cpu_has_feature(CPU_FTR_DAWR1)) {
+ host_dawr1 = mfspr(SPRN_DAWR1);
+ host_dawrx1 = mfspr(SPRN_DAWRX1);
+ }
+
+ if (vc->pcr)
+ mtspr(SPRN_PCR, vc->pcr | PCR_MASK);
+ mtspr(SPRN_DPDES, vc->dpdes);
+ mtspr(SPRN_VTB, vc->vtb);
+
+ local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR);
+ local_paca->kvm_hstate.host_spurr = mfspr(SPRN_SPURR);
+ mtspr(SPRN_PURR, vcpu->arch.purr);
+ mtspr(SPRN_SPURR, vcpu->arch.spurr);
+
+ if (dawr_enabled()) {
+ mtspr(SPRN_DAWR0, vcpu->arch.dawr0);
+ mtspr(SPRN_DAWRX0, vcpu->arch.dawrx0);
+ if (cpu_has_feature(CPU_FTR_DAWR1)) {
+ mtspr(SPRN_DAWR1, vcpu->arch.dawr1);
+ mtspr(SPRN_DAWRX1, vcpu->arch.dawrx1);
+ }
+ }
+ mtspr(SPRN_CIABR, vcpu->arch.ciabr);
+ mtspr(SPRN_IC, vcpu->arch.ic);
+
+ mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
+ (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
+
+ mtspr(SPRN_HFSCR, vcpu->arch.hfscr);
+
+ mtspr(SPRN_HSRR0, vcpu->arch.regs.nip);
+ mtspr(SPRN_HSRR1, (vcpu->arch.shregs.msr & ~MSR_HV) | MSR_ME);
+
+ /*
+ * On POWER9 DD2.1 and below, sometimes on a Hypervisor Data Storage
+ * Interrupt (HDSI) the HDSISR is not be updated at all.
+ *
+ * To work around this we put a canary value into the HDSISR before
+ * returning to a guest and then check for this canary when we take a
+ * HDSI. If we find the canary on a HDSI, we know the hardware didn't
+ * update the HDSISR. In this case we return to the guest to retake the
+ * HDSI which should correctly update the HDSISR the second time HDSI
+ * entry.
+ *
+ * Just do this on all p9 processors for now.
+ */
+ mtspr(SPRN_HDSISR, HDSISR_CANARY);
+
+ mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
+ mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
+ mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
+ mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
+
+ mtspr(SPRN_AMOR, ~0UL);
+
+ local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_HV_P9;
+
+ /*
+ * Hash host, hash guest, or radix guest with prefetch bug, all have
+ * to disable the MMU before switching to guest MMU state.
+ */
+ if (!radix_enabled() || !kvm_is_radix(kvm) ||
+ cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+ __mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
+
+ save_clear_host_mmu(kvm);
+
+ if (kvm_is_radix(kvm)) {
+ switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
+ if (!cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
+ __mtmsrd(0, 1); /* clear RI */
+
+ } else {
+ switch_mmu_to_guest_hpt(kvm, vcpu, lpcr);
+ }
+
+ /* TLBIEL uses LPID=LPIDR, so run this after setting guest LPID */
+ kvmppc_check_need_tlb_flush(kvm, vc->pcpu, nested);
+
+ /*
+ * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
+ * so set guest LPCR (with HDICE) before writing HDEC.
+ */
+ mtspr(SPRN_HDEC, hdec);
+
+ mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
+ mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
+ mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
+ mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
+
+ accumulate_time(vcpu, &vcpu->arch.guest_time);
+
+ kvmppc_p9_enter_guest(vcpu);
+
+ accumulate_time(vcpu, &vcpu->arch.rm_intr);
+
+ /* XXX: Could get these from r11/12 and paca exsave instead */
+ vcpu->arch.shregs.srr0 = mfspr(SPRN_SRR0);
+ vcpu->arch.shregs.srr1 = mfspr(SPRN_SRR1);
+ vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
+ vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
+
+ /* 0x2 bit for HSRR is only used by PR and P7/8 HV paths, clear it */
+ trap = local_paca->kvm_hstate.scratch0 & ~0x2;
+
+ /* HSRR interrupts leave MSR[RI] unchanged, SRR interrupts clear it. */
+ ri_set = false;
+ if (likely(trap > BOOK3S_INTERRUPT_MACHINE_CHECK)) {
+ if (trap != BOOK3S_INTERRUPT_SYSCALL &&
+ (vcpu->arch.shregs.msr & MSR_RI))
+ ri_set = true;
+ exsave = local_paca->exgen;
+ } else if (trap == BOOK3S_INTERRUPT_SYSTEM_RESET) {
+ exsave = local_paca->exnmi;
+ } else { /* trap == 0x200 */
+ exsave = local_paca->exmc;
+ }
+
+ vcpu->arch.regs.gpr[1] = local_paca->kvm_hstate.scratch1;
+ vcpu->arch.regs.gpr[3] = local_paca->kvm_hstate.scratch2;
+
+ /*
+ * Only set RI after reading machine check regs (DAR, DSISR, SRR0/1)
+ * and hstate scratch (which we need to move into exsave to make
+ * re-entrant vs SRESET/MCE)
+ */
+ if (ri_set) {
+ if (unlikely(!(mfmsr() & MSR_RI))) {
+ __mtmsrd(MSR_RI, 1);
+ WARN_ON_ONCE(1);
+ }
+ } else {
+ WARN_ON_ONCE(mfmsr() & MSR_RI);
+ __mtmsrd(MSR_RI, 1);
+ }
+
+ vcpu->arch.regs.gpr[9] = exsave[EX_R9/sizeof(u64)];
+ vcpu->arch.regs.gpr[10] = exsave[EX_R10/sizeof(u64)];
+ vcpu->arch.regs.gpr[11] = exsave[EX_R11/sizeof(u64)];
+ vcpu->arch.regs.gpr[12] = exsave[EX_R12/sizeof(u64)];
+ vcpu->arch.regs.gpr[13] = exsave[EX_R13/sizeof(u64)];
+ vcpu->arch.ppr = exsave[EX_PPR/sizeof(u64)];
+ vcpu->arch.cfar = exsave[EX_CFAR/sizeof(u64)];
+ vcpu->arch.regs.ctr = exsave[EX_CTR/sizeof(u64)];
+
+ vcpu->arch.last_inst = KVM_INST_FETCH_FAILED;
+
+ if (unlikely(trap == BOOK3S_INTERRUPT_MACHINE_CHECK)) {
+ vcpu->arch.fault_dar = exsave[EX_DAR/sizeof(u64)];
+ vcpu->arch.fault_dsisr = exsave[EX_DSISR/sizeof(u64)];
+ kvmppc_realmode_machine_check(vcpu);
+
+ } else if (unlikely(trap == BOOK3S_INTERRUPT_HMI)) {
+ kvmppc_realmode_hmi_handler();
+
+ } else if (trap == BOOK3S_INTERRUPT_H_EMUL_ASSIST) {
+ vcpu->arch.emul_inst = mfspr(SPRN_HEIR);
+
+ } else if (trap == BOOK3S_INTERRUPT_H_DATA_STORAGE) {
+ vcpu->arch.fault_dar = exsave[EX_DAR/sizeof(u64)];
+ vcpu->arch.fault_dsisr = exsave[EX_DSISR/sizeof(u64)];
+ vcpu->arch.fault_gpa = mfspr(SPRN_ASDR);
+
+ } else if (trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
+ vcpu->arch.fault_gpa = mfspr(SPRN_ASDR);
+
+ } else if (trap == BOOK3S_INTERRUPT_H_FAC_UNAVAIL) {
+ vcpu->arch.hfscr = mfspr(SPRN_HFSCR);
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+ /*
+ * Softpatch interrupt for transactional memory emulation cases
+ * on POWER9 DD2.2. This is early in the guest exit path - we
+ * haven't saved registers or done a treclaim yet.
+ */
+ } else if (trap == BOOK3S_INTERRUPT_HV_SOFTPATCH) {
+ vcpu->arch.emul_inst = mfspr(SPRN_HEIR);
+
+ /*
+ * The cases we want to handle here are those where the guest
+ * is in real suspend mode and is trying to transition to
+ * transactional mode.
+ */
+ if (local_paca->kvm_hstate.fake_suspend &&
+ (vcpu->arch.shregs.msr & MSR_TS_S)) {
+ if (kvmhv_p9_tm_emulation_early(vcpu)) {
+ /* Prevent it being handled again. */
+ trap = 0;
+ }
+ }
+#endif
+ }
+
+ accumulate_time(vcpu, &vcpu->arch.rm_exit);
+
+ /* Advance host PURR/SPURR by the amount used by guest */
+ purr = mfspr(SPRN_PURR);
+ spurr = mfspr(SPRN_SPURR);
+ mtspr(SPRN_PURR, local_paca->kvm_hstate.host_purr +
+ purr - vcpu->arch.purr);
+ mtspr(SPRN_SPURR, local_paca->kvm_hstate.host_spurr +
+ spurr - vcpu->arch.spurr);
+ vcpu->arch.purr = purr;
+ vcpu->arch.spurr = spurr;
+
+ vcpu->arch.ic = mfspr(SPRN_IC);
+ vcpu->arch.pid = mfspr(SPRN_PID);
+ vcpu->arch.psscr = mfspr(SPRN_PSSCR) & PSSCR_GUEST_VIS;
+
+ vcpu->arch.shregs.sprg0 = mfspr(SPRN_SPRG0);
+ vcpu->arch.shregs.sprg1 = mfspr(SPRN_SPRG1);
+ vcpu->arch.shregs.sprg2 = mfspr(SPRN_SPRG2);
+ vcpu->arch.shregs.sprg3 = mfspr(SPRN_SPRG3);
+
+ /* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
+ mtspr(SPRN_PSSCR, host_psscr |
+ (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
+ mtspr(SPRN_HFSCR, host_hfscr);
+ mtspr(SPRN_CIABR, host_ciabr);
+ mtspr(SPRN_DAWR0, host_dawr0);
+ mtspr(SPRN_DAWRX0, host_dawrx0);
+ if (cpu_has_feature(CPU_FTR_DAWR1)) {
+ mtspr(SPRN_DAWR1, host_dawr1);
+ mtspr(SPRN_DAWRX1, host_dawrx1);
+ }
+
+ if (kvm_is_radix(kvm)) {
+ /*
+ * Since this is radix, do a eieio; tlbsync; ptesync sequence
+ * in case we interrupted the guest between a tlbie and a
+ * ptesync.
+ */
+ asm volatile("eieio; tlbsync; ptesync");
+ }
+
+ /*
+ * cp_abort is required if the processor supports local copy-paste
+ * to clear the copy buffer that was under control of the guest.
+ */
+ if (cpu_has_feature(CPU_FTR_ARCH_31))
+ asm volatile(PPC_CP_ABORT);
+
+ vc->dpdes = mfspr(SPRN_DPDES);
+ vc->vtb = mfspr(SPRN_VTB);
+ mtspr(SPRN_DPDES, 0);
+ if (vc->pcr)
+ mtspr(SPRN_PCR, PCR_MASK);
+
+ if (vc->tb_offset_applied) {
+ u64 new_tb = mftb() - vc->tb_offset_applied;
+ mtspr(SPRN_TBU40, new_tb);
+ tb = mftb();
+ if ((tb & 0xffffff) < (new_tb & 0xffffff))
+ mtspr(SPRN_TBU40, new_tb + 0x1000000);
+ vc->tb_offset_applied = 0;
+ }
+
+ mtspr(SPRN_HDEC, 0x7fffffff);
+
+ save_clear_guest_mmu(kvm, vcpu);
+ switch_mmu_to_host(kvm, host_pidr);
+ local_paca->kvm_hstate.in_guest = KVM_GUEST_MODE_NONE;
+
+ /*
+ * If we are in real mode, only switch MMU on after the MMU is
+ * switched to host, to avoid the P9_RADIX_PREFETCH_BUG.
+ */
+ __mtmsrd(msr, 0);
+
+ end_timing(vcpu);
+
+ return trap;
+}
+EXPORT_SYMBOL_GPL(kvmhv_vcpu_entry_p9);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.