linux/arch/x86/include/asm/mshyperv.h
Tianyu Lan faff44069f x86/hyperv: Add Write/Read MSR registers via ghcb page
Hyperv provides GHCB protocol to write Synthetic Interrupt
Controller MSR registers in Isolation VM with AMD SEV SNP
and these registers are emulated by hypervisor directly.
Hyperv requires to write SINTx MSR registers twice. First
writes MSR via GHCB page to communicate with hypervisor
and then writes wrmsr instruction to talk with paravisor
which runs in VMPL0. Guest OS ID MSR also needs to be set
via GHCB page.

Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20211025122116.264793-7-ltykernel@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-10-28 11:22:38 +00:00

258 lines
6.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_MSHYPER_H
#define _ASM_X86_MSHYPER_H
#include <linux/types.h>
#include <linux/nmi.h>
#include <linux/msi.h>
#include <asm/io.h>
#include <asm/hyperv-tlfs.h>
#include <asm/nospec-branch.h>
#include <asm/paravirt.h>
#include <asm/mshyperv.h>
union hv_ghcb;
DECLARE_STATIC_KEY_FALSE(isolation_type_snp);
typedef int (*hyperv_fill_flush_list_func)(
struct hv_guest_mapping_flush_list *flush,
void *data);
#define hv_get_raw_timer() rdtsc_ordered()
void hyperv_vector_handler(struct pt_regs *regs);
#if IS_ENABLED(CONFIG_HYPERV)
extern int hyperv_init_cpuhp;
extern void *hv_hypercall_pg;
extern u64 hv_current_partition_id;
extern union hv_ghcb __percpu **hv_ghcb_pg;
int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages);
int hv_call_add_logical_proc(int node, u32 lp_index, u32 acpi_id);
int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags);
static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
{
u64 input_address = input ? virt_to_phys(input) : 0;
u64 output_address = output ? virt_to_phys(output) : 0;
u64 hv_status;
#ifdef CONFIG_X86_64
if (!hv_hypercall_pg)
return U64_MAX;
__asm__ __volatile__("mov %4, %%r8\n"
CALL_NOSPEC
: "=a" (hv_status), ASM_CALL_CONSTRAINT,
"+c" (control), "+d" (input_address)
: "r" (output_address),
THUNK_TARGET(hv_hypercall_pg)
: "cc", "memory", "r8", "r9", "r10", "r11");
#else
u32 input_address_hi = upper_32_bits(input_address);
u32 input_address_lo = lower_32_bits(input_address);
u32 output_address_hi = upper_32_bits(output_address);
u32 output_address_lo = lower_32_bits(output_address);
if (!hv_hypercall_pg)
return U64_MAX;
__asm__ __volatile__(CALL_NOSPEC
: "=A" (hv_status),
"+c" (input_address_lo), ASM_CALL_CONSTRAINT
: "A" (control),
"b" (input_address_hi),
"D"(output_address_hi), "S"(output_address_lo),
THUNK_TARGET(hv_hypercall_pg)
: "cc", "memory");
#endif /* !x86_64 */
return hv_status;
}
/* Fast hypercall with 8 bytes of input and no output */
static inline u64 hv_do_fast_hypercall8(u16 code, u64 input1)
{
u64 hv_status, control = (u64)code | HV_HYPERCALL_FAST_BIT;
#ifdef CONFIG_X86_64
{
__asm__ __volatile__(CALL_NOSPEC
: "=a" (hv_status), ASM_CALL_CONSTRAINT,
"+c" (control), "+d" (input1)
: THUNK_TARGET(hv_hypercall_pg)
: "cc", "r8", "r9", "r10", "r11");
}
#else
{
u32 input1_hi = upper_32_bits(input1);
u32 input1_lo = lower_32_bits(input1);
__asm__ __volatile__ (CALL_NOSPEC
: "=A"(hv_status),
"+c"(input1_lo),
ASM_CALL_CONSTRAINT
: "A" (control),
"b" (input1_hi),
THUNK_TARGET(hv_hypercall_pg)
: "cc", "edi", "esi");
}
#endif
return hv_status;
}
/* Fast hypercall with 16 bytes of input */
static inline u64 hv_do_fast_hypercall16(u16 code, u64 input1, u64 input2)
{
u64 hv_status, control = (u64)code | HV_HYPERCALL_FAST_BIT;
#ifdef CONFIG_X86_64
{
__asm__ __volatile__("mov %4, %%r8\n"
CALL_NOSPEC
: "=a" (hv_status), ASM_CALL_CONSTRAINT,
"+c" (control), "+d" (input1)
: "r" (input2),
THUNK_TARGET(hv_hypercall_pg)
: "cc", "r8", "r9", "r10", "r11");
}
#else
{
u32 input1_hi = upper_32_bits(input1);
u32 input1_lo = lower_32_bits(input1);
u32 input2_hi = upper_32_bits(input2);
u32 input2_lo = lower_32_bits(input2);
__asm__ __volatile__ (CALL_NOSPEC
: "=A"(hv_status),
"+c"(input1_lo), ASM_CALL_CONSTRAINT
: "A" (control), "b" (input1_hi),
"D"(input2_hi), "S"(input2_lo),
THUNK_TARGET(hv_hypercall_pg)
: "cc");
}
#endif
return hv_status;
}
extern struct hv_vp_assist_page **hv_vp_assist_page;
static inline struct hv_vp_assist_page *hv_get_vp_assist_page(unsigned int cpu)
{
if (!hv_vp_assist_page)
return NULL;
return hv_vp_assist_page[cpu];
}
void __init hyperv_init(void);
void hyperv_setup_mmu_ops(void);
void set_hv_tscchange_cb(void (*cb)(void));
void clear_hv_tscchange_cb(void);
void hyperv_stop_tsc_emulation(void);
int hyperv_flush_guest_mapping(u64 as);
int hyperv_flush_guest_mapping_range(u64 as,
hyperv_fill_flush_list_func fill_func, void *data);
int hyperv_fill_flush_guest_mapping_list(
struct hv_guest_mapping_flush_list *flush,
u64 start_gfn, u64 end_gfn);
#ifdef CONFIG_X86_64
void hv_apic_init(void);
void __init hv_init_spinlocks(void);
bool hv_vcpu_is_preempted(int vcpu);
#else
static inline void hv_apic_init(void) {}
#endif
static inline void hv_set_msi_entry_from_desc(union hv_msi_entry *msi_entry,
struct msi_desc *msi_desc)
{
msi_entry->address.as_uint32 = msi_desc->msg.address_lo;
msi_entry->data.as_uint32 = msi_desc->msg.data;
}
struct irq_domain *hv_create_pci_msi_domain(void);
int hv_map_ioapic_interrupt(int ioapic_id, bool level, int vcpu, int vector,
struct hv_interrupt_entry *entry);
int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry);
int hv_set_mem_host_visibility(unsigned long addr, int numpages, bool visible);
#ifdef CONFIG_AMD_MEM_ENCRYPT
void hv_ghcb_msr_write(u64 msr, u64 value);
void hv_ghcb_msr_read(u64 msr, u64 *value);
#else
static inline void hv_ghcb_msr_write(u64 msr, u64 value) {}
static inline void hv_ghcb_msr_read(u64 msr, u64 *value) {}
#endif
extern bool hv_isolation_type_snp(void);
static inline bool hv_is_synic_reg(unsigned int reg)
{
if ((reg >= HV_REGISTER_SCONTROL) &&
(reg <= HV_REGISTER_SINT15))
return true;
return false;
}
static inline u64 hv_get_register(unsigned int reg)
{
u64 value;
if (hv_is_synic_reg(reg) && hv_isolation_type_snp())
hv_ghcb_msr_read(reg, &value);
else
rdmsrl(reg, value);
return value;
}
static inline void hv_set_register(unsigned int reg, u64 value)
{
if (hv_is_synic_reg(reg) && hv_isolation_type_snp()) {
hv_ghcb_msr_write(reg, value);
/* Write proxy bit via wrmsl instruction */
if (reg >= HV_REGISTER_SINT0 &&
reg <= HV_REGISTER_SINT15)
wrmsrl(reg, value | 1 << 20);
} else {
wrmsrl(reg, value);
}
}
#else /* CONFIG_HYPERV */
static inline void hyperv_init(void) {}
static inline void hyperv_setup_mmu_ops(void) {}
static inline void set_hv_tscchange_cb(void (*cb)(void)) {}
static inline void clear_hv_tscchange_cb(void) {}
static inline void hyperv_stop_tsc_emulation(void) {};
static inline struct hv_vp_assist_page *hv_get_vp_assist_page(unsigned int cpu)
{
return NULL;
}
static inline int hyperv_flush_guest_mapping(u64 as) { return -1; }
static inline int hyperv_flush_guest_mapping_range(u64 as,
hyperv_fill_flush_list_func fill_func, void *data)
{
return -1;
}
static inline void hv_set_register(unsigned int reg, u64 value) { }
static inline u64 hv_get_register(unsigned int reg) { return 0; }
static inline int hv_set_mem_host_visibility(unsigned long addr, int numpages,
bool visible)
{
return -1;
}
#endif /* CONFIG_HYPERV */
#include <asm-generic/mshyperv.h>
#endif