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-rw-r--r--arch/x86/include/asm/sev.h6
-rw-r--r--arch/x86/kernel/sev-shared.c68
-rw-r--r--arch/x86/kernel/sev.c34
-rw-r--r--arch/x86/kernel/traps.c2
-rw-r--r--arch/x86/mm/mem_encrypt_identity.c9
5 files changed, 80 insertions, 39 deletions
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index fa5cd05d3b5b..ec060c433589 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -53,6 +53,7 @@ static inline u64 lower_bits(u64 val, unsigned int bits)
struct real_mode_header;
enum stack_type;
+struct ghcb;
/* Early IDT entry points for #VC handler */
extern void vc_no_ghcb(void);
@@ -81,6 +82,11 @@ static __always_inline void sev_es_nmi_complete(void)
__sev_es_nmi_complete();
}
extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
+extern enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
+ bool set_ghcb_msr,
+ struct es_em_ctxt *ctxt,
+ u64 exit_code, u64 exit_info_1,
+ u64 exit_info_2);
#else
static inline void sev_es_ist_enter(struct pt_regs *regs) { }
static inline void sev_es_ist_exit(void) { }
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
index ff1e82ff52d9..787dc5f568b5 100644
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c
@@ -94,25 +94,15 @@ static void vc_finish_insn(struct es_em_ctxt *ctxt)
ctxt->regs->ip += ctxt->insn.length;
}
-static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
- struct es_em_ctxt *ctxt,
- u64 exit_code, u64 exit_info_1,
- u64 exit_info_2)
+static enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
{
- enum es_result ret;
-
- /* Fill in protocol and format specifiers */
- ghcb->protocol_version = GHCB_PROTOCOL_MAX;
- ghcb->ghcb_usage = GHCB_DEFAULT_USAGE;
-
- ghcb_set_sw_exit_code(ghcb, exit_code);
- ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
- ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
+ u32 ret;
- sev_es_wr_ghcb_msr(__pa(ghcb));
- VMGEXIT();
+ ret = ghcb->save.sw_exit_info_1 & GENMASK_ULL(31, 0);
+ if (!ret)
+ return ES_OK;
- if ((ghcb->save.sw_exit_info_1 & 0xffffffff) == 1) {
+ if (ret == 1) {
u64 info = ghcb->save.sw_exit_info_2;
unsigned long v;
@@ -124,19 +114,40 @@ static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
((v == X86_TRAP_GP) || (v == X86_TRAP_UD)) &&
((info & SVM_EVTINJ_TYPE_MASK) == SVM_EVTINJ_TYPE_EXEPT)) {
ctxt->fi.vector = v;
+
if (info & SVM_EVTINJ_VALID_ERR)
ctxt->fi.error_code = info >> 32;
- ret = ES_EXCEPTION;
- } else {
- ret = ES_VMM_ERROR;
+
+ return ES_EXCEPTION;
}
- } else if (ghcb->save.sw_exit_info_1 & 0xffffffff) {
- ret = ES_VMM_ERROR;
- } else {
- ret = ES_OK;
}
- return ret;
+ return ES_VMM_ERROR;
+}
+
+enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, bool set_ghcb_msr,
+ struct es_em_ctxt *ctxt, u64 exit_code,
+ u64 exit_info_1, u64 exit_info_2)
+{
+ /* Fill in protocol and format specifiers */
+ ghcb->protocol_version = GHCB_PROTOCOL_MAX;
+ ghcb->ghcb_usage = GHCB_DEFAULT_USAGE;
+
+ ghcb_set_sw_exit_code(ghcb, exit_code);
+ ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
+ ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
+
+ /*
+ * Hyper-V unenlightened guests use a paravisor for communicating and
+ * GHCB pages are being allocated and set up by that paravisor. Linux
+ * should not change the GHCB page's physical address.
+ */
+ if (set_ghcb_msr)
+ sev_es_wr_ghcb_msr(__pa(ghcb));
+
+ VMGEXIT();
+
+ return verify_exception_info(ghcb, ctxt);
}
/*
@@ -413,7 +424,7 @@ static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
*/
sw_scratch = __pa(ghcb) + offsetof(struct ghcb, shared_buffer);
ghcb_set_sw_scratch(ghcb, sw_scratch);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO,
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_IOIO,
exit_info_1, exit_info_2);
if (ret != ES_OK)
return ret;
@@ -455,7 +466,8 @@ static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
ghcb_set_rax(ghcb, rax);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO, exit_info_1, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt,
+ SVM_EXIT_IOIO, exit_info_1, 0);
if (ret != ES_OK)
return ret;
@@ -486,7 +498,7 @@ static enum es_result vc_handle_cpuid(struct ghcb *ghcb,
/* xgetbv will cause #GP - use reset value for xcr0 */
ghcb_set_xcr0(ghcb, 1);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_CPUID, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_CPUID, 0, 0);
if (ret != ES_OK)
return ret;
@@ -511,7 +523,7 @@ static enum es_result vc_handle_rdtsc(struct ghcb *ghcb,
bool rdtscp = (exit_code == SVM_EXIT_RDTSCP);
enum es_result ret;
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, exit_code, 0, 0);
if (ret != ES_OK)
return ret;
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index 88c46136bbda..c195ffe58049 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -648,7 +648,8 @@ static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
ghcb_set_rdx(ghcb, regs->dx);
}
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_MSR, exit_info_1, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_MSR,
+ exit_info_1, 0);
if ((ret == ES_OK) && (!exit_info_1)) {
regs->ax = ghcb->save.rax;
@@ -867,7 +868,7 @@ static enum es_result vc_do_mmio(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
ghcb_set_sw_scratch(ghcb, ghcb_pa + offsetof(struct ghcb, shared_buffer));
- return sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, exit_info_1, exit_info_2);
+ return sev_es_ghcb_hv_call(ghcb, true, ctxt, exit_code, exit_info_1, exit_info_2);
}
static enum es_result vc_handle_mmio_twobyte_ops(struct ghcb *ghcb,
@@ -1117,7 +1118,7 @@ static enum es_result vc_handle_dr7_write(struct ghcb *ghcb,
/* Using a value of 0 for ExitInfo1 means RAX holds the value */
ghcb_set_rax(ghcb, val);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WRITE_DR7, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_WRITE_DR7, 0, 0);
if (ret != ES_OK)
return ret;
@@ -1147,7 +1148,7 @@ static enum es_result vc_handle_dr7_read(struct ghcb *ghcb,
static enum es_result vc_handle_wbinvd(struct ghcb *ghcb,
struct es_em_ctxt *ctxt)
{
- return sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WBINVD, 0, 0);
+ return sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_WBINVD, 0, 0);
}
static enum es_result vc_handle_rdpmc(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
@@ -1156,7 +1157,7 @@ static enum es_result vc_handle_rdpmc(struct ghcb *ghcb, struct es_em_ctxt *ctxt
ghcb_set_rcx(ghcb, ctxt->regs->cx);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_RDPMC, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_RDPMC, 0, 0);
if (ret != ES_OK)
return ret;
@@ -1197,7 +1198,7 @@ static enum es_result vc_handle_vmmcall(struct ghcb *ghcb,
if (x86_platform.hyper.sev_es_hcall_prepare)
x86_platform.hyper.sev_es_hcall_prepare(ghcb, ctxt->regs);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_VMMCALL, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, true, ctxt, SVM_EXIT_VMMCALL, 0, 0);
if (ret != ES_OK)
return ret;
@@ -1319,13 +1320,26 @@ static __always_inline void vc_forward_exception(struct es_em_ctxt *ctxt)
}
}
-static __always_inline bool on_vc_fallback_stack(struct pt_regs *regs)
+static __always_inline bool is_vc2_stack(unsigned long sp)
{
- unsigned long sp = (unsigned long)regs;
-
return (sp >= __this_cpu_ist_bottom_va(VC2) && sp < __this_cpu_ist_top_va(VC2));
}
+static __always_inline bool vc_from_invalid_context(struct pt_regs *regs)
+{
+ unsigned long sp, prev_sp;
+
+ sp = (unsigned long)regs;
+ prev_sp = regs->sp;
+
+ /*
+ * If the code was already executing on the VC2 stack when the #VC
+ * happened, let it proceed to the normal handling routine. This way the
+ * code executing on the VC2 stack can cause #VC exceptions to get handled.
+ */
+ return is_vc2_stack(sp) && !is_vc2_stack(prev_sp);
+}
+
static bool vc_raw_handle_exception(struct pt_regs *regs, unsigned long error_code)
{
struct ghcb_state state;
@@ -1406,7 +1420,7 @@ DEFINE_IDTENTRY_VC_KERNEL(exc_vmm_communication)
* But keep this here in case the noinstr annotations are violated due
* to bug elsewhere.
*/
- if (unlikely(on_vc_fallback_stack(regs))) {
+ if (unlikely(vc_from_invalid_context(regs))) {
instrumentation_begin();
panic("Can't handle #VC exception from unsupported context\n");
instrumentation_end();
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 6ca1454a65d4..43f70bc01762 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -709,7 +709,7 @@ asmlinkage __visible noinstr struct pt_regs *vc_switch_off_ist(struct pt_regs *r
stack = (unsigned long *)sp;
if (!get_stack_info_noinstr(stack, current, &info) || info.type == STACK_TYPE_ENTRY ||
- info.type >= STACK_TYPE_EXCEPTION_LAST)
+ info.type > STACK_TYPE_EXCEPTION_LAST)
sp = __this_cpu_ist_top_va(VC2);
sync:
diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
index f8c612902038..3f0abb403340 100644
--- a/arch/x86/mm/mem_encrypt_identity.c
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -27,6 +27,15 @@
#undef CONFIG_PARAVIRT_XXL
#undef CONFIG_PARAVIRT_SPINLOCKS
+/*
+ * This code runs before CPU feature bits are set. By default, the
+ * pgtable_l5_enabled() function uses bit X86_FEATURE_LA57 to determine if
+ * 5-level paging is active, so that won't work here. USE_EARLY_PGTABLE_L5
+ * is provided to handle this situation and, instead, use a variable that
+ * has been set by the early boot code.
+ */
+#define USE_EARLY_PGTABLE_L5
+
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/mem_encrypt.h>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-27 13:02:29 +0000