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kernel/arch/powerpc/kvm/book3s_hv_p9_entry.c
tqcq e5480701d3 init repo.
2024-07-22 17:22:30 +08:00

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// 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 __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) __accumulate_time(vcpu, next)
#define end_timing(vcpu) __accumulate_time(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);
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
tm_return_to_guest:
#endif
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)) {
/*
* Go straight back into the guest with the
* new NIP/MSR as set by TM emulation.
*/
mtspr(SPRN_HSRR0, vcpu->arch.regs.nip);
mtspr(SPRN_HSRR1, vcpu->arch.shregs.msr);
/*
* tm_return_to_guest re-loads SRR0/1, DAR,
* DSISR after RI is cleared, in case they had
* been clobbered by a MCE.
*/
__mtmsrd(0, 1); /* clear RI */
goto tm_return_to_guest;
}
}
#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.
*/
if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) &&
vcpu->arch.shregs.msr & MSR_TS_MASK)
msr |= MSR_TS_S;
__mtmsrd(msr, 0);
end_timing(vcpu);
return trap;
}
EXPORT_SYMBOL_GPL(kvmhv_vcpu_entry_p9);
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