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KVM/arm64 fixes for 6.10, take #1

Browse source 
- Large set of FP/SVE fixes for pKVM, addressing the fallout
   from the per-CPU data rework and making sure that the host
   is not involved in the FP/SVE switching any more
 
 - Allow FEAT_BTI to be enabled with NV now that FEAT_PAUTH
   is copletely supported
 
 - Fix for the respective priorities of Failed PAC, Illegal
   Execution state and Instruction Abort exceptions
 
 - Fix the handling of AArch32 instruction traps failing their
   condition code, which was broken by the introduction of
   ESR_EL2.ISS2
 
 - Allow vpcus running in AArch32 state to be restored in
   System mode
 
 - Fix AArch32 GPR restore that would lose the 64 bit state
   under some conditions
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Merge tag 'kvmarm-fixes-6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.10, take #1

- Large set of FP/SVE fixes for pKVM, addressing the fallout
  from the per-CPU data rework and making sure that the host
  is not involved in the FP/SVE switching any more

- Allow FEAT_BTI to be enabled with NV now that FEAT_PAUTH
  is copletely supported

- Fix for the respective priorities of Failed PAC, Illegal
  Execution state and Instruction Abort exceptions

- Fix the handling of AArch32 instruction traps failing their
  condition code, which was broken by the introduction of
  ESR_EL2.ISS2

- Allow vpcus running in AArch32 state to be restored in
  System mode

- Fix AArch32 GPR restore that would lose the 64 bit state
  under some conditions
This commit is contained in:
Paolo Bonzini 2024-06-05 06:32:18 -04:00
parent b50788f7cd afb91f5f8a
commit 45ce0314bf
21 changed files with 391 additions and 73 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
arch/arm64/include/asm/el2_setup.h
View file

@ -146,7 +146,7 @@
/* Coprocessor traps */
.macro __init_el2_cptr
__check_hvhe .LnVHE_\@, x1
mov x0, #(CPACR_EL1_FPEN_EL1EN | CPACR_EL1_FPEN_EL0EN)
mov x0, #CPACR_ELx_FPEN
msr cpacr_el1, x0
b .Lskip_set_cptr_\@
.LnVHE_\@:
@ -277,7 +277,7 @@
// (h)VHE case
mrs x0, cpacr_el1 // Disable SVE traps
orr x0, x0, #(CPACR_EL1_ZEN_EL1EN | CPACR_EL1_ZEN_EL0EN)
orr x0, x0, #CPACR_ELx_ZEN
msr cpacr_el1, x0
b .Lskip_set_cptr_\@
@ -298,7 +298,7 @@
// (h)VHE case
mrs x0, cpacr_el1 // Disable SME traps
orr x0, x0, #(CPACR_EL1_SMEN_EL0EN | CPACR_EL1_SMEN_EL1EN)
orr x0, x0, #CPACR_ELx_SMEN
msr cpacr_el1, x0
b .Lskip_set_cptr_sme_\@

6
arch/arm64/include/asm/kvm_arm.h
View file

@ -305,6 +305,12 @@
GENMASK(19, 14) | \
BIT(11))
#define CPTR_VHE_EL2_RES0 (GENMASK(63, 32) | \
GENMASK(27, 26) | \
GENMASK(23, 22) | \
GENMASK(19, 18) | \
GENMASK(15, 0))
/* Hyp Debug Configuration Register bits */
#define MDCR_EL2_E2TB_MASK (UL(0x3))
#define MDCR_EL2_E2TB_SHIFT (UL(24))

71
arch/arm64/include/asm/kvm_emulate.h
View file

@ -557,6 +557,68 @@ static __always_inline void kvm_incr_pc(struct kvm_vcpu *vcpu)
vcpu_set_flag((v), e); \
} while (0)
#define __build_check_all_or_none(r, bits) \
BUILD_BUG_ON(((r) & (bits)) && ((r) & (bits)) != (bits))
#define __cpacr_to_cptr_clr(clr, set) \
({ \
u64 cptr = 0; \
\
if ((set) & CPACR_ELx_FPEN) \
cptr |= CPTR_EL2_TFP; \
if ((set) & CPACR_ELx_ZEN) \
cptr |= CPTR_EL2_TZ; \
if ((set) & CPACR_ELx_SMEN) \
cptr |= CPTR_EL2_TSM; \
if ((clr) & CPACR_ELx_TTA) \
cptr |= CPTR_EL2_TTA; \
if ((clr) & CPTR_EL2_TAM) \
cptr |= CPTR_EL2_TAM; \
if ((clr) & CPTR_EL2_TCPAC) \
cptr |= CPTR_EL2_TCPAC; \
\
cptr; \
})
#define __cpacr_to_cptr_set(clr, set) \
({ \
u64 cptr = 0; \
\
if ((clr) & CPACR_ELx_FPEN) \
cptr |= CPTR_EL2_TFP; \
if ((clr) & CPACR_ELx_ZEN) \
cptr |= CPTR_EL2_TZ; \
if ((clr) & CPACR_ELx_SMEN) \
cptr |= CPTR_EL2_TSM; \
if ((set) & CPACR_ELx_TTA) \
cptr |= CPTR_EL2_TTA; \
if ((set) & CPTR_EL2_TAM) \
cptr |= CPTR_EL2_TAM; \
if ((set) & CPTR_EL2_TCPAC) \
cptr |= CPTR_EL2_TCPAC; \
\
cptr; \
})
#define cpacr_clear_set(clr, set) \
do { \
BUILD_BUG_ON((set) & CPTR_VHE_EL2_RES0); \
BUILD_BUG_ON((clr) & CPACR_ELx_E0POE); \
__build_check_all_or_none((clr), CPACR_ELx_FPEN); \
__build_check_all_or_none((set), CPACR_ELx_FPEN); \
__build_check_all_or_none((clr), CPACR_ELx_ZEN); \
__build_check_all_or_none((set), CPACR_ELx_ZEN); \
__build_check_all_or_none((clr), CPACR_ELx_SMEN); \
__build_check_all_or_none((set), CPACR_ELx_SMEN); \
\
if (has_vhe() || has_hvhe()) \
sysreg_clear_set(cpacr_el1, clr, set); \
else \
sysreg_clear_set(cptr_el2, \
__cpacr_to_cptr_clr(clr, set), \
__cpacr_to_cptr_set(clr, set));\
} while (0)
static __always_inline void kvm_write_cptr_el2(u64 val)
{
if (has_vhe() || has_hvhe())
@ -570,17 +632,16 @@ static __always_inline u64 kvm_get_reset_cptr_el2(struct kvm_vcpu *vcpu)
u64 val;
if (has_vhe()) {
val = (CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN |
CPACR_EL1_ZEN_EL1EN);
val = (CPACR_ELx_FPEN | CPACR_EL1_ZEN_EL1EN);
if (cpus_have_final_cap(ARM64_SME))
val |= CPACR_EL1_SMEN_EL1EN;
} else if (has_hvhe()) {
val = (CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN);
val = CPACR_ELx_FPEN;
if (!vcpu_has_sve(vcpu) || !guest_owns_fp_regs())
val |= CPACR_EL1_ZEN_EL1EN | CPACR_EL1_ZEN_EL0EN;
val |= CPACR_ELx_ZEN;
if (cpus_have_final_cap(ARM64_SME))
val |= CPACR_EL1_SMEN_EL1EN | CPACR_EL1_SMEN_EL0EN;
val |= CPACR_ELx_SMEN;
} else {
val = CPTR_NVHE_EL2_RES1;

25
arch/arm64/include/asm/kvm_host.h
View file

@ -76,6 +76,7 @@ static inline enum kvm_mode kvm_get_mode(void) { return KVM_MODE_NONE; };
DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
extern unsigned int __ro_after_init kvm_sve_max_vl;
extern unsigned int __ro_after_init kvm_host_sve_max_vl;
int __init kvm_arm_init_sve(void);
u32 __attribute_const__ kvm_target_cpu(void);
@ -521,6 +522,20 @@ struct kvm_cpu_context {
u64 *vncr_array;
};
struct cpu_sve_state {
__u64 zcr_el1;
/*
* Ordering is important since __sve_save_state/__sve_restore_state
* relies on it.
*/
__u32 fpsr;
__u32 fpcr;
/* Must be SVE_VQ_BYTES (128 bit) aligned. */
__u8 sve_regs[];
};
/*
* This structure is instantiated on a per-CPU basis, and contains
* data that is:
@ -534,7 +549,15 @@ struct kvm_cpu_context {
*/
struct kvm_host_data {
struct kvm_cpu_context host_ctxt;
struct user_fpsimd_state *fpsimd_state; /* hyp VA */
/*
* All pointers in this union are hyp VA.
* sve_state is only used in pKVM and if system_supports_sve().
*/
union {
struct user_fpsimd_state *fpsimd_state;
struct cpu_sve_state *sve_state;
};
/* Ownership of the FP regs */
enum {

4
arch/arm64/include/asm/kvm_hyp.h
View file

@ -111,7 +111,8 @@ void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu);
void __fpsimd_save_state(struct user_fpsimd_state *fp_regs);
void __fpsimd_restore_state(struct user_fpsimd_state *fp_regs);
void __sve_restore_state(void *sve_pffr, u32 *fpsr);
void __sve_save_state(void *sve_pffr, u32 *fpsr, int save_ffr);
void __sve_restore_state(void *sve_pffr, u32 *fpsr, int restore_ffr);
u64 __guest_enter(struct kvm_vcpu *vcpu);
@ -142,5 +143,6 @@ extern u64 kvm_nvhe_sym(id_aa64smfr0_el1_sys_val);
extern unsigned long kvm_nvhe_sym(__icache_flags);
extern unsigned int kvm_nvhe_sym(kvm_arm_vmid_bits);
extern unsigned int kvm_nvhe_sym(kvm_host_sve_max_vl);
#endif /* __ARM64_KVM_HYP_H__ */

9
arch/arm64/include/asm/kvm_pkvm.h
View file

@ -128,4 +128,13 @@ static inline unsigned long hyp_ffa_proxy_pages(void)
return (2 * KVM_FFA_MBOX_NR_PAGES) + DIV_ROUND_UP(desc_max, PAGE_SIZE);
}
static inline size_t pkvm_host_sve_state_size(void)
{
if (!system_supports_sve())
return 0;
return size_add(sizeof(struct cpu_sve_state),
SVE_SIG_REGS_SIZE(sve_vq_from_vl(kvm_host_sve_max_vl)));
}
#endif /* __ARM64_KVM_PKVM_H__ */

76
arch/arm64/kvm/arm.c
View file

@ -1931,6 +1931,11 @@ static unsigned long nvhe_percpu_order(void)
return size ? get_order(size) : 0;
}
static size_t pkvm_host_sve_state_order(void)
{
return get_order(pkvm_host_sve_state_size());
}
/* A lookup table holding the hypervisor VA for each vector slot */
static void *hyp_spectre_vector_selector[BP_HARDEN_EL2_SLOTS];
@ -2310,12 +2315,20 @@ static void __init teardown_subsystems(void)
static void __init teardown_hyp_mode(void)
{
bool free_sve = system_supports_sve() && is_protected_kvm_enabled();
int cpu;
free_hyp_pgds();
for_each_possible_cpu(cpu) {
free_page(per_cpu(kvm_arm_hyp_stack_page, cpu));
free_pages(kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu], nvhe_percpu_order());
if (free_sve) {
struct cpu_sve_state *sve_state;
sve_state = per_cpu_ptr_nvhe_sym(kvm_host_data, cpu)->sve_state;
free_pages((unsigned long) sve_state, pkvm_host_sve_state_order());
}
}
}
@ -2398,6 +2411,58 @@ static int __init kvm_hyp_init_protection(u32 hyp_va_bits)
return 0;
}
static int init_pkvm_host_sve_state(void)
{
int cpu;
if (!system_supports_sve())
return 0;
/* Allocate pages for host sve state in protected mode. */
for_each_possible_cpu(cpu) {
struct page *page = alloc_pages(GFP_KERNEL, pkvm_host_sve_state_order());
if (!page)
return -ENOMEM;
per_cpu_ptr_nvhe_sym(kvm_host_data, cpu)->sve_state = page_address(page);
}
/*
* Don't map the pages in hyp since these are only used in protected
* mode, which will (re)create its own mapping when initialized.
*/
return 0;
}
/*
* Finalizes the initialization of hyp mode, once everything else is initialized
* and the initialziation process cannot fail.
*/
static void finalize_init_hyp_mode(void)
{
int cpu;
if (system_supports_sve() && is_protected_kvm_enabled()) {
for_each_possible_cpu(cpu) {
struct cpu_sve_state *sve_state;
sve_state = per_cpu_ptr_nvhe_sym(kvm_host_data, cpu)->sve_state;
per_cpu_ptr_nvhe_sym(kvm_host_data, cpu)->sve_state =
kern_hyp_va(sve_state);
}
} else {
for_each_possible_cpu(cpu) {
struct user_fpsimd_state *fpsimd_state;
fpsimd_state = &per_cpu_ptr_nvhe_sym(kvm_host_data, cpu)->host_ctxt.fp_regs;
per_cpu_ptr_nvhe_sym(kvm_host_data, cpu)->fpsimd_state =
kern_hyp_va(fpsimd_state);
}
}
}
static void pkvm_hyp_init_ptrauth(void)
{
struct kvm_cpu_context *hyp_ctxt;
@ -2566,6 +2631,10 @@ static int __init init_hyp_mode(void)
goto out_err;
}
err = init_pkvm_host_sve_state();
if (err)
goto out_err;
err = kvm_hyp_init_protection(hyp_va_bits);
if (err) {
kvm_err("Failed to init hyp memory protection\n");
@ -2730,6 +2799,13 @@ static __init int kvm_arm_init(void)
if (err)
goto out_subs;
/*
* This should be called after initialization is done and failure isn't
* possible anymore.
*/
if (!in_hyp_mode)
finalize_init_hyp_mode();
kvm_arm_initialised = true;
return 0;

21
arch/arm64/kvm/emulate-nested.c
View file

@ -2181,16 +2181,23 @@ void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu)
if (forward_traps(vcpu, HCR_NV))
return;
spsr = vcpu_read_sys_reg(vcpu, SPSR_EL2);
spsr = kvm_check_illegal_exception_return(vcpu, spsr);
/* Check for an ERETAx */
esr = kvm_vcpu_get_esr(vcpu);
if (esr_iss_is_eretax(esr) && !kvm_auth_eretax(vcpu, &elr)) {
/*
* Oh no, ERETAx failed to authenticate. If we have
* FPACCOMBINE, deliver an exception right away. If we
* don't, then let the mangled ELR value trickle down the
* Oh no, ERETAx failed to authenticate.
*
* If we have FPACCOMBINE and we don't have a pending
* Illegal Execution State exception (which has priority
* over FPAC), deliver an exception right away.
*
* Otherwise, let the mangled ELR value trickle down the
* ERET handling, and the guest will have a little surprise.
*/
if (kvm_has_pauth(vcpu->kvm, FPACCOMBINE)) {
if (kvm_has_pauth(vcpu->kvm, FPACCOMBINE) && !(spsr & PSR_IL_BIT)) {
esr &= ESR_ELx_ERET_ISS_ERETA;
esr |= FIELD_PREP(ESR_ELx_EC_MASK, ESR_ELx_EC_FPAC);
kvm_inject_nested_sync(vcpu, esr);
@ -2201,17 +2208,11 @@ void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu)
preempt_disable();
kvm_arch_vcpu_put(vcpu);
spsr = __vcpu_sys_reg(vcpu, SPSR_EL2);
spsr = kvm_check_illegal_exception_return(vcpu, spsr);
if (!esr_iss_is_eretax(esr))
elr = __vcpu_sys_reg(vcpu, ELR_EL2);
trace_kvm_nested_eret(vcpu, elr, spsr);
/*
* Note that the current exception level is always the virtual EL2,
* since we set HCR_EL2.NV bit only when entering the virtual EL2.
*/
*vcpu_pc(vcpu) = elr;
*vcpu_cpsr(vcpu) = spsr;

11
arch/arm64/kvm/fpsimd.c
View file

@ -90,6 +90,13 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu)
fpsimd_save_and_flush_cpu_state();
}
}
/*
* If normal guests gain SME support, maintain this behavior for pKVM
* guests, which don't support SME.
*/
WARN_ON(is_protected_kvm_enabled() && system_supports_sme() &&
read_sysreg_s(SYS_SVCR));
}
/*
@ -161,9 +168,7 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu)
if (has_vhe() && system_supports_sme()) {
/* Also restore EL0 state seen on entry */
if (vcpu_get_flag(vcpu, HOST_SME_ENABLED))
sysreg_clear_set(CPACR_EL1, 0,
CPACR_EL1_SMEN_EL0EN |
CPACR_EL1_SMEN_EL1EN);
sysreg_clear_set(CPACR_EL1, 0, CPACR_ELx_SMEN);
else
sysreg_clear_set(CPACR_EL1,
CPACR_EL1_SMEN_EL0EN,

3
arch/arm64/kvm/guest.c
View file

@ -251,6 +251,7 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
case PSR_AA32_MODE_SVC:
case PSR_AA32_MODE_ABT:
case PSR_AA32_MODE_UND:
case PSR_AA32_MODE_SYS:
if (!vcpu_el1_is_32bit(vcpu))
return -EINVAL;
break;
@ -276,7 +277,7 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
if (*vcpu_cpsr(vcpu) & PSR_MODE32_BIT) {
int i, nr_reg;
switch (*vcpu_cpsr(vcpu)) {
switch (*vcpu_cpsr(vcpu) & PSR_AA32_MODE_MASK) {
/*
* Either we are dealing with user mode, and only the
* first 15 registers (+ PC) must be narrowed to 32bit.

18
arch/arm64/kvm/hyp/aarch32.c
View file

@ -50,9 +50,23 @@ bool kvm_condition_valid32(const struct kvm_vcpu *vcpu)
u32 cpsr_cond;
int cond;
/* Top two bits non-zero? Unconditional. */
if (kvm_vcpu_get_esr(vcpu) >> 30)
/*
* These are the exception classes that could fire with a
* conditional instruction.
*/
switch (kvm_vcpu_trap_get_class(vcpu)) {
case ESR_ELx_EC_CP15_32:
case ESR_ELx_EC_CP15_64:
case ESR_ELx_EC_CP14_MR:
case ESR_ELx_EC_CP14_LS:
case ESR_ELx_EC_FP_ASIMD:
case ESR_ELx_EC_CP10_ID:
case ESR_ELx_EC_CP14_64:
case ESR_ELx_EC_SVC32:
break;
default:
return true;
}
/* Is condition field valid? */
cond = kvm_vcpu_get_condition(vcpu);

6
arch/arm64/kvm/hyp/fpsimd.S
View file

@ -25,3 +25,9 @@ SYM_FUNC_START(__sve_restore_state)
sve_load 0, x1, x2, 3
ret
SYM_FUNC_END(__sve_restore_state)
SYM_FUNC_START(__sve_save_state)
mov x2, #1
sve_save 0, x1, x2, 3
ret
SYM_FUNC_END(__sve_save_state)

36
arch/arm64/kvm/hyp/include/hyp/switch.h
View file

@ -316,10 +316,24 @@ static inline void __hyp_sve_restore_guest(struct kvm_vcpu *vcpu)
{
sve_cond_update_zcr_vq(vcpu_sve_max_vq(vcpu) - 1, SYS_ZCR_EL2);
__sve_restore_state(vcpu_sve_pffr(vcpu),
&vcpu->arch.ctxt.fp_regs.fpsr);
&vcpu->arch.ctxt.fp_regs.fpsr,
true);
write_sysreg_el1(__vcpu_sys_reg(vcpu, ZCR_EL1), SYS_ZCR);
}
static inline void __hyp_sve_save_host(void)
{
struct cpu_sve_state *sve_state = *host_data_ptr(sve_state);
sve_state->zcr_el1 = read_sysreg_el1(SYS_ZCR);
write_sysreg_s(ZCR_ELx_LEN_MASK, SYS_ZCR_EL2);
__sve_save_state(sve_state->sve_regs + sve_ffr_offset(kvm_host_sve_max_vl),
&sve_state->fpsr,
true);
}
static void kvm_hyp_save_fpsimd_host(struct kvm_vcpu *vcpu);
/*
* We trap the first access to the FP/SIMD to save the host context and
* restore the guest context lazily.
@ -330,7 +344,6 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
{
bool sve_guest;
u8 esr_ec;
u64 reg;
if (!system_supports_fpsimd())
return false;
@ -353,24 +366,15 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
/* Valid trap. Switch the context: */
/* First disable enough traps to allow us to update the registers */
if (has_vhe() || has_hvhe()) {
reg = CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN;
if (sve_guest)
reg |= CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN;
sysreg_clear_set(cpacr_el1, 0, reg);
} else {
reg = CPTR_EL2_TFP;
if (sve_guest)
reg |= CPTR_EL2_TZ;
sysreg_clear_set(cptr_el2, reg, 0);
}
if (sve_guest || (is_protected_kvm_enabled() && system_supports_sve()))
cpacr_clear_set(0, CPACR_ELx_FPEN | CPACR_ELx_ZEN);
else
cpacr_clear_set(0, CPACR_ELx_FPEN);
isb();
/* Write out the host state if it's in the registers */
if (host_owns_fp_regs())
__fpsimd_save_state(*host_data_ptr(fpsimd_state));
kvm_hyp_save_fpsimd_host(vcpu);
/* Restore the guest state */
if (sve_guest)

1
arch/arm64/kvm/hyp/include/nvhe/pkvm.h
View file

@ -59,7 +59,6 @@ static inline bool pkvm_hyp_vcpu_is_protected(struct pkvm_hyp_vcpu *hyp_vcpu)
}
void pkvm_hyp_vm_table_init(void *tbl);
void pkvm_host_fpsimd_state_init(void);
int __pkvm_init_vm(struct kvm *host_kvm, unsigned long vm_hva,
unsigned long pgd_hva);

84
arch/arm64/kvm/hyp/nvhe/hyp-main.c
View file

@ -23,20 +23,80 @@ DEFINE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
void __kvm_hyp_host_forward_smc(struct kvm_cpu_context *host_ctxt);
static void __hyp_sve_save_guest(struct kvm_vcpu *vcpu)
{
__vcpu_sys_reg(vcpu, ZCR_EL1) = read_sysreg_el1(SYS_ZCR);
/*
* On saving/restoring guest sve state, always use the maximum VL for
* the guest. The layout of the data when saving the sve state depends
* on the VL, so use a consistent (i.e., the maximum) guest VL.
*/
sve_cond_update_zcr_vq(vcpu_sve_max_vq(vcpu) - 1, SYS_ZCR_EL2);
__sve_save_state(vcpu_sve_pffr(vcpu), &vcpu->arch.ctxt.fp_regs.fpsr, true);
write_sysreg_s(ZCR_ELx_LEN_MASK, SYS_ZCR_EL2);
}
static void __hyp_sve_restore_host(void)
{
struct cpu_sve_state *sve_state = *host_data_ptr(sve_state);
/*
* On saving/restoring host sve state, always use the maximum VL for
* the host. The layout of the data when saving the sve state depends
* on the VL, so use a consistent (i.e., the maximum) host VL.
*
* Setting ZCR_EL2 to ZCR_ELx_LEN_MASK sets the effective length
* supported by the system (or limited at EL3).
*/
write_sysreg_s(ZCR_ELx_LEN_MASK, SYS_ZCR_EL2);
__sve_restore_state(sve_state->sve_regs + sve_ffr_offset(kvm_host_sve_max_vl),
&sve_state->fpsr,
true);
write_sysreg_el1(sve_state->zcr_el1, SYS_ZCR);
}
static void fpsimd_sve_flush(void)
{
*host_data_ptr(fp_owner) = FP_STATE_HOST_OWNED;
}
static void fpsimd_sve_sync(struct kvm_vcpu *vcpu)
{
if (!guest_owns_fp_regs())
return;
cpacr_clear_set(0, CPACR_ELx_FPEN | CPACR_ELx_ZEN);
isb();
if (vcpu_has_sve(vcpu))
__hyp_sve_save_guest(vcpu);
else
__fpsimd_save_state(&vcpu->arch.ctxt.fp_regs);
if (system_supports_sve())
__hyp_sve_restore_host();
else
__fpsimd_restore_state(*host_data_ptr(fpsimd_state));
*host_data_ptr(fp_owner) = FP_STATE_HOST_OWNED;
}
static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
{
struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu;
fpsimd_sve_flush();
hyp_vcpu->vcpu.arch.ctxt = host_vcpu->arch.ctxt;
hyp_vcpu->vcpu.arch.sve_state = kern_hyp_va(host_vcpu->arch.sve_state);
hyp_vcpu->vcpu.arch.sve_max_vl = host_vcpu->arch.sve_max_vl;
/* Limit guest vector length to the maximum supported by the host. */
hyp_vcpu->vcpu.arch.sve_max_vl = min(host_vcpu->arch.sve_max_vl, kvm_host_sve_max_vl);
hyp_vcpu->vcpu.arch.hw_mmu = host_vcpu->arch.hw_mmu;
hyp_vcpu->vcpu.arch.hcr_el2 = host_vcpu->arch.hcr_el2;
hyp_vcpu->vcpu.arch.mdcr_el2 = host_vcpu->arch.mdcr_el2;
hyp_vcpu->vcpu.arch.cptr_el2 = host_vcpu->arch.cptr_el2;
hyp_vcpu->vcpu.arch.iflags = host_vcpu->arch.iflags;
@ -54,10 +114,11 @@ static void sync_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
struct vgic_v3_cpu_if *host_cpu_if = &host_vcpu->arch.vgic_cpu.vgic_v3;
unsigned int i;
fpsimd_sve_sync(&hyp_vcpu->vcpu);
host_vcpu->arch.ctxt = hyp_vcpu->vcpu.arch.ctxt;
host_vcpu->arch.hcr_el2 = hyp_vcpu->vcpu.arch.hcr_el2;
host_vcpu->arch.cptr_el2 = hyp_vcpu->vcpu.arch.cptr_el2;
host_vcpu->arch.fault = hyp_vcpu->vcpu.arch.fault;
@ -79,6 +140,17 @@ static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt)
struct pkvm_hyp_vcpu *hyp_vcpu;
struct kvm *host_kvm;
/*
* KVM (and pKVM) doesn't support SME guests for now, and
* ensures that SME features aren't enabled in pstate when
* loading a vcpu. Therefore, if SME features enabled the host
* is misbehaving.
*/
if (unlikely(system_supports_sme() && read_sysreg_s(SYS_SVCR))) {
ret = -EINVAL;
goto out;
}
host_kvm = kern_hyp_va(host_vcpu->kvm);
hyp_vcpu = pkvm_load_hyp_vcpu(host_kvm->arch.pkvm.handle,
host_vcpu->vcpu_idx);
@ -405,11 +477,7 @@ void handle_trap(struct kvm_cpu_context *host_ctxt)
handle_host_smc(host_ctxt);
break;
case ESR_ELx_EC_SVE:
if (has_hvhe())
sysreg_clear_set(cpacr_el1, 0, (CPACR_EL1_ZEN_EL1EN |
CPACR_EL1_ZEN_EL0EN));
else
sysreg_clear_set(cptr_el2, CPTR_EL2_TZ, 0);
cpacr_clear_set(0, CPACR_ELx_ZEN);
isb();
sve_cond_update_zcr_vq(ZCR_ELx_LEN_MASK, SYS_ZCR_EL2);
break;

17
arch/arm64/kvm/hyp/nvhe/pkvm.c
View file

@ -18,6 +18,8 @@ unsigned long __icache_flags;
/* Used by kvm_get_vttbr(). */
unsigned int kvm_arm_vmid_bits;
unsigned int kvm_host_sve_max_vl;
/*
* Set trap register values based on features in ID_AA64PFR0.
*/
@ -63,7 +65,7 @@ static void pvm_init_traps_aa64pfr0(struct kvm_vcpu *vcpu)
/* Trap SVE */
if (!FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_SVE), feature_ids)) {
if (has_hvhe())
cptr_clear |= CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN;
cptr_clear |= CPACR_ELx_ZEN;
else
cptr_set |= CPTR_EL2_TZ;
}
@ -247,17 +249,6 @@ void pkvm_hyp_vm_table_init(void *tbl)
vm_table = tbl;
}
void pkvm_host_fpsimd_state_init(void)
{
unsigned long i;
for (i = 0; i < hyp_nr_cpus; i++) {
struct kvm_host_data *host_data = per_cpu_ptr(&kvm_host_data, i);
host_data->fpsimd_state = &host_data->host_ctxt.fp_regs;
}
}
/*
* Return the hyp vm structure corresponding to the handle.
*/
@ -586,6 +577,8 @@ int __pkvm_init_vcpu(pkvm_handle_t handle, struct kvm_vcpu *host_vcpu,
if (ret)
unmap_donated_memory(hyp_vcpu, sizeof(*hyp_vcpu));
hyp_vcpu->vcpu.arch.cptr_el2 = kvm_get_reset_cptr_el2(&hyp_vcpu->vcpu);
return ret;
}

25
arch/arm64/kvm/hyp/nvhe/setup.c
View file

@ -67,6 +67,28 @@ static int divide_memory_pool(void *virt, unsigned long size)
return 0;
}
static int pkvm_create_host_sve_mappings(void)
{
void *start, *end;
int ret, i;
if (!system_supports_sve())
return 0;
for (i = 0; i < hyp_nr_cpus; i++) {
struct kvm_host_data *host_data = per_cpu_ptr(&kvm_host_data, i);
struct cpu_sve_state *sve_state = host_data->sve_state;
start = kern_hyp_va(sve_state);
end = start + PAGE_ALIGN(pkvm_host_sve_state_size());
ret = pkvm_create_mappings(start, end, PAGE_HYP);
if (ret)
return ret;
}
return 0;
}
static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size,
unsigned long *per_cpu_base,
u32 hyp_va_bits)
@ -125,6 +147,8 @@ static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size,
return ret;
}
pkvm_create_host_sve_mappings();
/*
* Map the host sections RO in the hypervisor, but transfer the
* ownership from the host to the hypervisor itself to make sure they
@ -300,7 +324,6 @@ void __noreturn __pkvm_init_finalise(void)
goto out;
pkvm_hyp_vm_table_init(vm_table_base);
pkvm_host_fpsimd_state_init();
out:
/*
* We tail-called to here from handle___pkvm_init() and will not return,

24
arch/arm64/kvm/hyp/nvhe/switch.c
View file

@ -48,15 +48,14 @@ static void __activate_traps(struct kvm_vcpu *vcpu)
val |= has_hvhe() ? CPACR_EL1_TTA : CPTR_EL2_TTA;
if (cpus_have_final_cap(ARM64_SME)) {
if (has_hvhe())
val &= ~(CPACR_EL1_SMEN_EL1EN | CPACR_EL1_SMEN_EL0EN);
val &= ~CPACR_ELx_SMEN;
else
val |= CPTR_EL2_TSM;
}
if (!guest_owns_fp_regs()) {
if (has_hvhe())
val &= ~(CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN |
CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN);
val &= ~(CPACR_ELx_FPEN | CPACR_ELx_ZEN);
else
val |= CPTR_EL2_TFP | CPTR_EL2_TZ;
@ -182,6 +181,25 @@ static bool kvm_handle_pvm_sys64(struct kvm_vcpu *vcpu, u64 *exit_code)
kvm_handle_pvm_sysreg(vcpu, exit_code));
}
static void kvm_hyp_save_fpsimd_host(struct kvm_vcpu *vcpu)
{
/*
* Non-protected kvm relies on the host restoring its sve state.
* Protected kvm restores the host's sve state as not to reveal that
* fpsimd was used by a guest nor leak upper sve bits.
*/
if (unlikely(is_protected_kvm_enabled() && system_supports_sve())) {
__hyp_sve_save_host();
/* Re-enable SVE traps if not supported for the guest vcpu. */
if (!vcpu_has_sve(vcpu))
cpacr_clear_set(CPACR_ELx_ZEN, 0);
} else {
__fpsimd_save_state(*host_data_ptr(fpsimd_state));
}
}
static const exit_handler_fn hyp_exit_handlers[] = {
[0 ... ESR_ELx_EC_MAX] = NULL,
[ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15_32,

12
arch/arm64/kvm/hyp/vhe/switch.c
View file

@ -93,8 +93,7 @@ static void __activate_traps(struct kvm_vcpu *vcpu)
val = read_sysreg(cpacr_el1);
val |= CPACR_ELx_TTA;
val &= ~(CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN |
CPACR_EL1_SMEN_EL0EN | CPACR_EL1_SMEN_EL1EN);
val &= ~(CPACR_ELx_ZEN | CPACR_ELx_SMEN);
/*
* With VHE (HCR.E2H == 1), accesses to CPACR_EL1 are routed to
@ -109,9 +108,9 @@ static void __activate_traps(struct kvm_vcpu *vcpu)
if (guest_owns_fp_regs()) {
if (vcpu_has_sve(vcpu))
val |= CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN;
val |= CPACR_ELx_ZEN;
} else {
val &= ~(CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN);
val &= ~CPACR_ELx_FPEN;
__activate_traps_fpsimd32(vcpu);
}
@ -262,6 +261,11 @@ static bool kvm_hyp_handle_eret(struct kvm_vcpu *vcpu, u64 *exit_code)
return true;
}
static void kvm_hyp_save_fpsimd_host(struct kvm_vcpu *vcpu)
{
__fpsimd_save_state(*host_data_ptr(fpsimd_state));
}
static const exit_handler_fn hyp_exit_handlers[] = {
[0 ... ESR_ELx_EC_MAX] = NULL,
[ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15_32,

6
arch/arm64/kvm/nested.c
View file

@ -58,8 +58,10 @@ static u64 limit_nv_id_reg(u32 id, u64 val)
break;
case SYS_ID_AA64PFR1_EL1:
/* Only support SSBS */
val &= NV_FTR(PFR1, SSBS);
/* Only support BTI, SSBS, CSV2_frac */
val &= (NV_FTR(PFR1, BT) |
NV_FTR(PFR1, SSBS) |
NV_FTR(PFR1, CSV2_frac));
break;
case SYS_ID_AA64MMFR0_EL1:

3
arch/arm64/kvm/reset.c
View file

@ -32,6 +32,7 @@
/* Maximum phys_shift supported for any VM on this host */
static u32 __ro_after_init kvm_ipa_limit;
unsigned int __ro_after_init kvm_host_sve_max_vl;
/*
* ARMv8 Reset Values
@ -51,6 +52,8 @@ int __init kvm_arm_init_sve(void)
{
if (system_supports_sve()) {
kvm_sve_max_vl = sve_max_virtualisable_vl();
kvm_host_sve_max_vl = sve_max_vl();
kvm_nvhe_sym(kvm_host_sve_max_vl) = kvm_host_sve_max_vl;
/*
* The get_sve_reg()/set_sve_reg() ioctl interface will need