linux/arch/arm64/kvm/nested.c
Marc Zyngier 03fb54d0aa KVM: arm64: nv: Add support for HCRX_EL2
HCRX_EL2 has an interesting effect on HFGITR_EL2, as it conditions
the traps of TLBI*nXS.

Expand the FGT support to add a new Fine Grained Filter that will
get checked when the instruction gets trapped, allowing the shadow
register to override the trap as needed.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Jing Zhang <jingzhangos@google.com>
Link: https://lore.kernel.org/r/20230815183903.2735724-29-maz@kernel.org
2023-08-17 10:00:28 +01:00

163 lines
4.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2017 - Columbia University and Linaro Ltd.
* Author: Jintack Lim <jintack.lim@linaro.org>
*/
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_nested.h>
#include <asm/sysreg.h>
#include "sys_regs.h"
/* Protection against the sysreg repainting madness... */
#define NV_FTR(r, f) ID_AA64##r##_EL1_##f
/*
* Our emulated CPU doesn't support all the possible features. For the
* sake of simplicity (and probably mental sanity), wipe out a number
* of feature bits we don't intend to support for the time being.
* This list should get updated as new features get added to the NV
* support, and new extension to the architecture.
*/
void access_nested_id_reg(struct kvm_vcpu *v, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
u32 id = reg_to_encoding(r);
u64 val, tmp;
val = p->regval;
switch (id) {
case SYS_ID_AA64ISAR0_EL1:
/* Support everything but TME, O.S. and Range TLBIs */
val &= ~(NV_FTR(ISAR0, TLB) |
NV_FTR(ISAR0, TME));
break;
case SYS_ID_AA64ISAR1_EL1:
/* Support everything but PtrAuth and Spec Invalidation */
val &= ~(GENMASK_ULL(63, 56) |
NV_FTR(ISAR1, SPECRES) |
NV_FTR(ISAR1, GPI) |
NV_FTR(ISAR1, GPA) |
NV_FTR(ISAR1, API) |
NV_FTR(ISAR1, APA));
break;
case SYS_ID_AA64PFR0_EL1:
/* No AMU, MPAM, S-EL2, RAS or SVE */
val &= ~(GENMASK_ULL(55, 52) |
NV_FTR(PFR0, AMU) |
NV_FTR(PFR0, MPAM) |
NV_FTR(PFR0, SEL2) |
NV_FTR(PFR0, RAS) |
NV_FTR(PFR0, SVE) |
NV_FTR(PFR0, EL3) |
NV_FTR(PFR0, EL2) |
NV_FTR(PFR0, EL1));
/* 64bit EL1/EL2/EL3 only */
val |= FIELD_PREP(NV_FTR(PFR0, EL1), 0b0001);
val |= FIELD_PREP(NV_FTR(PFR0, EL2), 0b0001);
val |= FIELD_PREP(NV_FTR(PFR0, EL3), 0b0001);
break;
case SYS_ID_AA64PFR1_EL1:
/* Only support SSBS */
val &= NV_FTR(PFR1, SSBS);
break;
case SYS_ID_AA64MMFR0_EL1:
/* Hide ECV, ExS, Secure Memory */
val &= ~(NV_FTR(MMFR0, ECV) |
NV_FTR(MMFR0, EXS) |
NV_FTR(MMFR0, TGRAN4_2) |
NV_FTR(MMFR0, TGRAN16_2) |
NV_FTR(MMFR0, TGRAN64_2) |
NV_FTR(MMFR0, SNSMEM));
/* Disallow unsupported S2 page sizes */
switch (PAGE_SIZE) {
case SZ_64K:
val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN16_2), 0b0001);
fallthrough;
case SZ_16K:
val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN4_2), 0b0001);
fallthrough;
case SZ_4K:
/* Support everything */
break;
}
/*
* Since we can't support a guest S2 page size smaller than
* the host's own page size (due to KVM only populating its
* own S2 using the kernel's page size), advertise the
* limitation using FEAT_GTG.
*/
switch (PAGE_SIZE) {
case SZ_4K:
val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN4_2), 0b0010);
fallthrough;
case SZ_16K:
val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN16_2), 0b0010);
fallthrough;
case SZ_64K:
val |= FIELD_PREP(NV_FTR(MMFR0, TGRAN64_2), 0b0010);
break;
}
/* Cap PARange to 48bits */
tmp = FIELD_GET(NV_FTR(MMFR0, PARANGE), val);
if (tmp > 0b0101) {
val &= ~NV_FTR(MMFR0, PARANGE);
val |= FIELD_PREP(NV_FTR(MMFR0, PARANGE), 0b0101);
}
break;
case SYS_ID_AA64MMFR1_EL1:
val &= (NV_FTR(MMFR1, HCX) |
NV_FTR(MMFR1, PAN) |
NV_FTR(MMFR1, LO) |
NV_FTR(MMFR1, HPDS) |
NV_FTR(MMFR1, VH) |
NV_FTR(MMFR1, VMIDBits));
break;
case SYS_ID_AA64MMFR2_EL1:
val &= ~(NV_FTR(MMFR2, BBM) |
NV_FTR(MMFR2, TTL) |
GENMASK_ULL(47, 44) |
NV_FTR(MMFR2, ST) |
NV_FTR(MMFR2, CCIDX) |
NV_FTR(MMFR2, VARange));
/* Force TTL support */
val |= FIELD_PREP(NV_FTR(MMFR2, TTL), 0b0001);
break;
case SYS_ID_AA64DFR0_EL1:
/* Only limited support for PMU, Debug, BPs and WPs */
val &= (NV_FTR(DFR0, PMUVer) |
NV_FTR(DFR0, WRPs) |
NV_FTR(DFR0, BRPs) |
NV_FTR(DFR0, DebugVer));
/* Cap Debug to ARMv8.1 */
tmp = FIELD_GET(NV_FTR(DFR0, DebugVer), val);
if (tmp > 0b0111) {
val &= ~NV_FTR(DFR0, DebugVer);
val |= FIELD_PREP(NV_FTR(DFR0, DebugVer), 0b0111);
}
break;
default:
/* Unknown register, just wipe it clean */
val = 0;
break;
}
p->regval = val;
}