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target/ppc: Filter mtmsr[d] input before setting MSR 

PowerISA says that mtmsr[d] "does not alter MSR[HV], MSR[S], MSR[ME], or
MSR[LE]", but the current code only filters the GPR-provided value if
L=1. This behavior caused some problems in FreeBSD, and a build option
was added to work around the issue [1], but it seems that the bug was
not reported in launchpad/gitlab. This patch address the issue in qemu,
so the option on FreeBSD should no longer be required.

[1] https://cgit.freebsd.org/src/commit/?id=4efb1ca7d2a44cfb33d7f9e18bd92f8d68dcfee0

Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Message-Id: <20211015181940.197982-1-matheus.ferst@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Matheus Ferst 2021-10-15 15:19:40 -03:00 committed by David Gibson
parent 5ff1dfdf66
commit 6fa5726be6
2 changed files with 41 additions and 33 deletions
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1
target/ppc/cpu.h
View File

@ -314,6 +314,7 @@ typedef struct ppc_v3_pate_t {
#define MSR_AP 23 /* Access privilege state on 602 hflags */
#define MSR_VSX 23 /* Vector Scalar Extension (ISA 2.06 and later) x hflags */
#define MSR_SA 22 /* Supervisor access mode on 602 hflags */
#define MSR_S 22 /* Secure state */
#define MSR_KEY 19 /* key bit on 603e */
#define MSR_POW 18 /* Power management */
#define MSR_TGPR 17 /* TGPR usage on 602/603 x */

73
target/ppc/translate.c
View File

@ -4934,32 +4934,40 @@ static void gen_mtmsrd(DisasContext *ctx)
CHK_SV;
#if !defined(CONFIG_USER_ONLY)
TCGv t0, t1;
target_ulong mask;
t0 = tcg_temp_new();
t1 = tcg_temp_new();
gen_icount_io_start(ctx);
if (ctx->opcode & 0x00010000) {
/* L=1 form only updates EE and RI */
TCGv t0 = tcg_temp_new();
TCGv t1 = tcg_temp_new();
tcg_gen_andi_tl(t0, cpu_gpr[rS(ctx->opcode)],
(1 << MSR_RI) | (1 << MSR_EE));
tcg_gen_andi_tl(t1, cpu_msr,
~(target_ulong)((1 << MSR_RI) | (1 << MSR_EE)));
tcg_gen_or_tl(t1, t1, t0);
gen_helper_store_msr(cpu_env, t1);
tcg_temp_free(t0);
tcg_temp_free(t1);
mask = (1ULL << MSR_RI) | (1ULL << MSR_EE);
} else {
/* mtmsrd does not alter HV, S, ME, or LE */
mask = ~((1ULL << MSR_LE) | (1ULL << MSR_ME) | (1ULL << MSR_S) |
(1ULL << MSR_HV));
/*
* XXX: we need to update nip before the store if we enter
* power saving mode, we will exit the loop directly from
* ppc_store_msr
*/
gen_update_nip(ctx, ctx->base.pc_next);
gen_helper_store_msr(cpu_env, cpu_gpr[rS(ctx->opcode)]);
}
tcg_gen_andi_tl(t0, cpu_gpr[rS(ctx->opcode)], mask);
tcg_gen_andi_tl(t1, cpu_msr, ~mask);
tcg_gen_or_tl(t0, t0, t1);
gen_helper_store_msr(cpu_env, t0);
/* Must stop the translation as machine state (may have) changed */
ctx->base.is_jmp = DISAS_EXIT_UPDATE;
tcg_temp_free(t0);
tcg_temp_free(t1);
#endif /* !defined(CONFIG_USER_ONLY) */
}
#endif /* defined(TARGET_PPC64) */
@ -4969,23 +4977,19 @@ static void gen_mtmsr(DisasContext *ctx)
CHK_SV;
#if !defined(CONFIG_USER_ONLY)
TCGv t0, t1;
target_ulong mask = 0xFFFFFFFF;
t0 = tcg_temp_new();
t1 = tcg_temp_new();
gen_icount_io_start(ctx);
if (ctx->opcode & 0x00010000) {
/* L=1 form only updates EE and RI */
TCGv t0 = tcg_temp_new();
TCGv t1 = tcg_temp_new();
tcg_gen_andi_tl(t0, cpu_gpr[rS(ctx->opcode)],
(1 << MSR_RI) | (1 << MSR_EE));
tcg_gen_andi_tl(t1, cpu_msr,
~(target_ulong)((1 << MSR_RI) | (1 << MSR_EE)));
tcg_gen_or_tl(t1, t1, t0);
gen_helper_store_msr(cpu_env, t1);
tcg_temp_free(t0);
tcg_temp_free(t1);
mask &= (1ULL << MSR_RI) | (1ULL << MSR_EE);
} else {
TCGv msr = tcg_temp_new();
/* mtmsr does not alter S, ME, or LE */
mask &= ~((1ULL << MSR_LE) | (1ULL << MSR_ME) | (1ULL << MSR_S));
/*
* XXX: we need to update nip before the store if we enter
@ -4993,16 +4997,19 @@ static void gen_mtmsr(DisasContext *ctx)
* ppc_store_msr
*/
gen_update_nip(ctx, ctx->base.pc_next);
#if defined(TARGET_PPC64)
tcg_gen_deposit_tl(msr, cpu_msr, cpu_gpr[rS(ctx->opcode)], 0, 32);
#else
tcg_gen_mov_tl(msr, cpu_gpr[rS(ctx->opcode)]);
#endif
gen_helper_store_msr(cpu_env, msr);
tcg_temp_free(msr);
}
tcg_gen_andi_tl(t0, cpu_gpr[rS(ctx->opcode)], mask);
tcg_gen_andi_tl(t1, cpu_msr, ~mask);
tcg_gen_or_tl(t0, t0, t1);
gen_helper_store_msr(cpu_env, t0);
/* Must stop the translation as machine state (may have) changed */
ctx->base.is_jmp = DISAS_EXIT_UPDATE;
tcg_temp_free(t0);
tcg_temp_free(t1);
#endif
}