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-rw-r--r--arch/powerpc/kvm/tm.S398
1 files changed, 398 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/tm.S b/arch/powerpc/kvm/tm.S
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+++ b/arch/powerpc/kvm/tm.S
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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ *
+ * Derived from book3s_hv_rmhandlers.S, which is:
+ *
+ * Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
+ */
+
+#include <asm/reg.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/export.h>
+#include <asm/tm.h>
+#include <asm/cputable.h>
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+#define VCPU_GPRS_TM(reg) (((reg) * ULONG_SIZE) + VCPU_GPR_TM)
+
+/*
+ * Save transactional state and TM-related registers.
+ * Called with:
+ * - r3 pointing to the vcpu struct
+ * - r4 containing the MSR with current TS bits:
+ * (For HV KVM, it is VCPU_MSR ; For PR KVM, it is host MSR).
+ * - r5 containing a flag indicating that non-volatile registers
+ * must be preserved.
+ * If r5 == 0, this can modify all checkpointed registers, but
+ * restores r1, r2 before exit. If r5 != 0, this restores the
+ * MSR TM/FP/VEC/VSX bits to their state on entry.
+ */
+_GLOBAL(__kvmppc_save_tm)
+ mflr r0
+ std r0, PPC_LR_STKOFF(r1)
+ stdu r1, -SWITCH_FRAME_SIZE(r1)
+
+ mr r9, r3
+ cmpdi cr7, r5, 0
+
+ /* Turn on TM. */
+ mfmsr r8
+ mr r10, r8
+ li r0, 1
+ rldimi r8, r0, MSR_TM_LG, 63-MSR_TM_LG
+ ori r8, r8, MSR_FP
+ oris r8, r8, (MSR_VEC | MSR_VSX)@h
+ mtmsrd r8
+
+ rldicl. r4, r4, 64 - MSR_TS_S_LG, 62
+ beq 1f /* TM not active in guest. */
+
+ std r1, HSTATE_SCRATCH2(r13)
+ std r3, HSTATE_SCRATCH1(r13)
+
+ /* Save CR on the stack - even if r5 == 0 we need to get cr7 back. */
+ mfcr r6
+ SAVE_GPR(6, r1)
+
+ /* Save DSCR so we can restore it to avoid running with user value */
+ mfspr r7, SPRN_DSCR
+ SAVE_GPR(7, r1)
+
+ /*
+ * We are going to do treclaim., which will modify all checkpointed
+ * registers. Save the non-volatile registers on the stack if
+ * preservation of non-volatile state has been requested.
+ */
+ beq cr7, 3f
+ SAVE_NVGPRS(r1)
+
+ /* MSR[TS] will be 0 (non-transactional) once we do treclaim. */
+ li r0, 0
+ rldimi r10, r0, MSR_TS_S_LG, 63 - MSR_TS_T_LG
+ SAVE_GPR(10, r1) /* final MSR value */
+3:
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+BEGIN_FTR_SECTION
+ /* Emulation of the treclaim instruction needs TEXASR before treclaim */
+ mfspr r6, SPRN_TEXASR
+ std r6, VCPU_ORIG_TEXASR(r3)
+END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_HV_ASSIST)
+#endif
+
+ /* Clear the MSR RI since r1, r13 are all going to be foobar. */
+ li r5, 0
+ mtmsrd r5, 1
+
+ li r3, TM_CAUSE_KVM_RESCHED
+
+ /* All GPRs are volatile at this point. */
+ TRECLAIM(R3)
+
+ /* Temporarily store r13 and r9 so we have some regs to play with */
+ SET_SCRATCH0(r13)
+ GET_PACA(r13)
+ std r9, PACATMSCRATCH(r13)
+ ld r9, HSTATE_SCRATCH1(r13)
+
+ /* Save away PPR soon so we don't run with user value. */
+ std r0, VCPU_GPRS_TM(0)(r9)
+ mfspr r0, SPRN_PPR
+ HMT_MEDIUM
+
+ /* Reload stack pointer. */
+ std r1, VCPU_GPRS_TM(1)(r9)
+ ld r1, HSTATE_SCRATCH2(r13)
+
+ /* Set MSR RI now we have r1 and r13 back. */
+ std r2, VCPU_GPRS_TM(2)(r9)
+ li r2, MSR_RI
+ mtmsrd r2, 1
+
+ /* Reload TOC pointer. */
+ LOAD_PACA_TOC()
+
+ /* Save all but r0-r2, r9 & r13 */
+ reg = 3
+ .rept 29
+ .if (reg != 9) && (reg != 13)
+ std reg, VCPU_GPRS_TM(reg)(r9)
+ .endif
+ reg = reg + 1
+ .endr
+ /* ... now save r13 */
+ GET_SCRATCH0(r4)
+ std r4, VCPU_GPRS_TM(13)(r9)
+ /* ... and save r9 */
+ ld r4, PACATMSCRATCH(r13)
+ std r4, VCPU_GPRS_TM(9)(r9)
+
+ /* Restore host DSCR and CR values, after saving guest values */
+ mfcr r6
+ mfspr r7, SPRN_DSCR
+ stw r6, VCPU_CR_TM(r9)
+ std r7, VCPU_DSCR_TM(r9)
+ REST_GPR(6, r1)
+ REST_GPR(7, r1)
+ mtcr r6
+ mtspr SPRN_DSCR, r7
+
+ /* Save away checkpointed SPRs. */
+ std r0, VCPU_PPR_TM(r9)
+ mflr r5
+ mfctr r7
+ mfspr r8, SPRN_AMR
+ mfspr r10, SPRN_TAR
+ mfxer r11
+ std r5, VCPU_LR_TM(r9)
+ std r7, VCPU_CTR_TM(r9)
+ std r8, VCPU_AMR_TM(r9)
+ std r10, VCPU_TAR_TM(r9)
+ std r11, VCPU_XER_TM(r9)
+
+ /* Save FP/VSX. */
+ addi r3, r9, VCPU_FPRS_TM
+ bl store_fp_state
+ addi r3, r9, VCPU_VRS_TM
+ bl store_vr_state
+ mfspr r6, SPRN_VRSAVE
+ stw r6, VCPU_VRSAVE_TM(r9)
+
+ /* Restore non-volatile registers if requested to */
+ beq cr7, 1f
+ REST_NVGPRS(r1)
+ REST_GPR(10, r1)
+1:
+ /*
+ * We need to save these SPRs after the treclaim so that the software
+ * error code is recorded correctly in the TEXASR. Also the user may
+ * change these outside of a transaction, so they must always be
+ * context switched.
+ */
+ mfspr r7, SPRN_TEXASR
+ std r7, VCPU_TEXASR(r9)
+ mfspr r5, SPRN_TFHAR
+ mfspr r6, SPRN_TFIAR
+ std r5, VCPU_TFHAR(r9)
+ std r6, VCPU_TFIAR(r9)
+
+ /* Restore MSR state if requested */
+ beq cr7, 2f
+ mtmsrd r10, 0
+2:
+ addi r1, r1, SWITCH_FRAME_SIZE
+ ld r0, PPC_LR_STKOFF(r1)
+ mtlr r0
+ blr
+
+/*
+ * _kvmppc_save_tm_pr() is a wrapper around __kvmppc_save_tm(), so that it can
+ * be invoked from C function by PR KVM only.
+ */
+_GLOBAL(_kvmppc_save_tm_pr)
+ mflr r0
+ std r0, PPC_LR_STKOFF(r1)
+ stdu r1, -PPC_MIN_STKFRM(r1)
+
+ mfspr r8, SPRN_TAR
+ std r8, PPC_MIN_STKFRM-8(r1)
+
+ li r5, 1 /* preserve non-volatile registers */
+ bl __kvmppc_save_tm
+
+ ld r8, PPC_MIN_STKFRM-8(r1)
+ mtspr SPRN_TAR, r8
+
+ addi r1, r1, PPC_MIN_STKFRM
+ ld r0, PPC_LR_STKOFF(r1)
+ mtlr r0
+ blr
+
+EXPORT_SYMBOL_GPL(_kvmppc_save_tm_pr);
+
+/*
+ * Restore transactional state and TM-related registers.
+ * Called with:
+ * - r3 pointing to the vcpu struct.
+ * - r4 is the guest MSR with desired TS bits:
+ * For HV KVM, it is VCPU_MSR
+ * For PR KVM, it is provided by caller
+ * - r5 containing a flag indicating that non-volatile registers
+ * must be preserved.
+ * If r5 == 0, this potentially modifies all checkpointed registers, but
+ * restores r1, r2 from the PACA before exit.
+ * If r5 != 0, this restores the MSR TM/FP/VEC/VSX bits to their state on entry.
+ */
+_GLOBAL(__kvmppc_restore_tm)
+ mflr r0
+ std r0, PPC_LR_STKOFF(r1)
+
+ cmpdi cr7, r5, 0
+
+ /* Turn on TM/FP/VSX/VMX so we can restore them. */
+ mfmsr r5
+ mr r10, r5
+ li r6, MSR_TM >> 32
+ sldi r6, r6, 32
+ or r5, r5, r6
+ ori r5, r5, MSR_FP
+ oris r5, r5, (MSR_VEC | MSR_VSX)@h
+ mtmsrd r5
+
+ /*
+ * The user may change these outside of a transaction, so they must
+ * always be context switched.
+ */
+ ld r5, VCPU_TFHAR(r3)
+ ld r6, VCPU_TFIAR(r3)
+ ld r7, VCPU_TEXASR(r3)
+ mtspr SPRN_TFHAR, r5
+ mtspr SPRN_TFIAR, r6
+ mtspr SPRN_TEXASR, r7
+
+ mr r5, r4
+ rldicl. r5, r5, 64 - MSR_TS_S_LG, 62
+ beq 9f /* TM not active in guest */
+
+ /* Make sure the failure summary is set, otherwise we'll program check
+ * when we trechkpt. It's possible that this might have been not set
+ * on a kvmppc_set_one_reg() call but we shouldn't let this crash the
+ * host.
+ */
+ oris r7, r7, (TEXASR_FS)@h
+ mtspr SPRN_TEXASR, r7
+
+ /*
+ * Make a stack frame and save non-volatile registers if requested.
+ */
+ stdu r1, -SWITCH_FRAME_SIZE(r1)
+ std r1, HSTATE_SCRATCH2(r13)
+
+ mfcr r6
+ mfspr r7, SPRN_DSCR
+ SAVE_GPR(2, r1)
+ SAVE_GPR(6, r1)
+ SAVE_GPR(7, r1)
+
+ beq cr7, 4f
+ SAVE_NVGPRS(r1)
+
+ /* MSR[TS] will be 1 (suspended) once we do trechkpt */
+ li r0, 1
+ rldimi r10, r0, MSR_TS_S_LG, 63 - MSR_TS_T_LG
+ SAVE_GPR(10, r1) /* final MSR value */
+4:
+ /*
+ * We need to load up the checkpointed state for the guest.
+ * We need to do this early as it will blow away any GPRs, VSRs and
+ * some SPRs.
+ */
+
+ mr r31, r3
+ addi r3, r31, VCPU_FPRS_TM
+ bl load_fp_state
+ addi r3, r31, VCPU_VRS_TM
+ bl load_vr_state
+ mr r3, r31
+ lwz r7, VCPU_VRSAVE_TM(r3)
+ mtspr SPRN_VRSAVE, r7
+
+ ld r5, VCPU_LR_TM(r3)
+ lwz r6, VCPU_CR_TM(r3)
+ ld r7, VCPU_CTR_TM(r3)
+ ld r8, VCPU_AMR_TM(r3)
+ ld r9, VCPU_TAR_TM(r3)
+ ld r10, VCPU_XER_TM(r3)
+ mtlr r5
+ mtcr r6
+ mtctr r7
+ mtspr SPRN_AMR, r8
+ mtspr SPRN_TAR, r9
+ mtxer r10
+
+ /*
+ * Load up PPR and DSCR values but don't put them in the actual SPRs
+ * till the last moment to avoid running with userspace PPR and DSCR for
+ * too long.
+ */
+ ld r29, VCPU_DSCR_TM(r3)
+ ld r30, VCPU_PPR_TM(r3)
+
+ /* Clear the MSR RI since r1, r13 are all going to be foobar. */
+ li r5, 0
+ mtmsrd r5, 1
+
+ /* Load GPRs r0-r28 */
+ reg = 0
+ .rept 29
+ ld reg, VCPU_GPRS_TM(reg)(r31)
+ reg = reg + 1
+ .endr
+
+ mtspr SPRN_DSCR, r29
+ mtspr SPRN_PPR, r30
+
+ /* Load final GPRs */
+ ld 29, VCPU_GPRS_TM(29)(r31)
+ ld 30, VCPU_GPRS_TM(30)(r31)
+ ld 31, VCPU_GPRS_TM(31)(r31)
+
+ /* TM checkpointed state is now setup. All GPRs are now volatile. */
+ TRECHKPT
+
+ /* Now let's get back the state we need. */
+ HMT_MEDIUM
+ GET_PACA(r13)
+ ld r1, HSTATE_SCRATCH2(r13)
+ REST_GPR(7, r1)
+ mtspr SPRN_DSCR, r7
+
+ /* Set the MSR RI since we have our registers back. */
+ li r5, MSR_RI
+ mtmsrd r5, 1
+
+ /* Restore TOC pointer and CR */
+ REST_GPR(2, r1)
+ REST_GPR(6, r1)
+ mtcr r6
+
+ /* Restore non-volatile registers if requested to. */
+ beq cr7, 5f
+ REST_GPR(10, r1)
+ REST_NVGPRS(r1)
+
+5: addi r1, r1, SWITCH_FRAME_SIZE
+ ld r0, PPC_LR_STKOFF(r1)
+ mtlr r0
+
+9: /* Restore MSR bits if requested */
+ beqlr cr7
+ mtmsrd r10, 0
+ blr
+
+/*
+ * _kvmppc_restore_tm_pr() is a wrapper around __kvmppc_restore_tm(), so that it
+ * can be invoked from C function by PR KVM only.
+ */
+_GLOBAL(_kvmppc_restore_tm_pr)
+ mflr r0
+ std r0, PPC_LR_STKOFF(r1)
+ stdu r1, -PPC_MIN_STKFRM(r1)
+
+ /* save TAR so that it can be recovered later */
+ mfspr r8, SPRN_TAR
+ std r8, PPC_MIN_STKFRM-8(r1)
+
+ li r5, 1
+ bl __kvmppc_restore_tm
+
+ ld r8, PPC_MIN_STKFRM-8(r1)
+ mtspr SPRN_TAR, r8
+
+ addi r1, r1, PPC_MIN_STKFRM
+ ld r0, PPC_LR_STKOFF(r1)
+ mtlr r0
+ blr
+
+EXPORT_SYMBOL_GPL(_kvmppc_restore_tm_pr);
+#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */