[PATCH] Revert "x86/sev: Expose sev_es_ghcb_hv_call() for use by HyperV"
From: Borislav Petkov
Date: Wed Jul 27 2022 - 10:48:24 EST
This reverts commit 007faec014cb5d26983c1f86fd08c6539b41392e.
Now that hyperv does its own protocol negotiation:
49d6a3c062a1 ("x86/Hyper-V: Add SEV negotiate protocol support in Isolation VM")
revert this exposure of the sev_es_ghcb_hv_call() helper.
Cc: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
Cc: Wei Liu <wei.liu@xxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Link: https://lore.kernel.org/r/20220614014553.1915929-1-ltykernel@xxxxxxxxx
---
My plan is to queue this now and send it to Linus as an urgent fix so
that 5.19 gets released clean, without that export.
So if you folks see an issue, holler now pls.
Thx.
arch/x86/include/asm/sev.h | 7 +------
arch/x86/kernel/sev-shared.c | 25 +++++++++----------------
arch/x86/kernel/sev.c | 17 ++++++++---------
3 files changed, 18 insertions(+), 31 deletions(-)
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index 19514524f0f8..4a23e52fe0ee 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -72,7 +72,6 @@ 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);
@@ -156,11 +155,7 @@ 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);
+
static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs)
{
int rc;
diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
index b478edf43bec..3a5b0c9c4fcc 100644
--- a/arch/x86/kernel/sev-shared.c
+++ b/arch/x86/kernel/sev-shared.c
@@ -219,9 +219,10 @@ static enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt
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)
+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)
{
/* Fill in protocol and format specifiers */
ghcb->protocol_version = ghcb_version;
@@ -231,14 +232,7 @@ enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb, bool set_ghcb_msr,
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));
-
+ sev_es_wr_ghcb_msr(__pa(ghcb));
VMGEXIT();
return verify_exception_info(ghcb, ctxt);
@@ -795,7 +789,7 @@ 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, true, ctxt, SVM_EXIT_IOIO,
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO,
exit_info_1, exit_info_2);
if (ret != ES_OK)
return ret;
@@ -837,8 +831,7 @@ 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, true, ctxt,
- SVM_EXIT_IOIO, exit_info_1, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO, exit_info_1, 0);
if (ret != ES_OK)
return ret;
@@ -894,7 +887,7 @@ 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, true, ctxt, SVM_EXIT_CPUID, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_CPUID, 0, 0);
if (ret != ES_OK)
return ret;
@@ -919,7 +912,7 @@ 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, true, ctxt, exit_code, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, 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 c05f0124c410..63dc626627a0 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -786,7 +786,7 @@ static int vmgexit_psc(struct snp_psc_desc *desc)
ghcb_set_sw_scratch(ghcb, (u64)__pa(data));
/* This will advance the shared buffer data points to. */
- ret = sev_es_ghcb_hv_call(ghcb, true, &ctxt, SVM_VMGEXIT_PSC, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, &ctxt, SVM_VMGEXIT_PSC, 0, 0);
/*
* Page State Change VMGEXIT can pass error code through
@@ -1212,8 +1212,7 @@ 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, true, ctxt, SVM_EXIT_MSR,
- exit_info_1, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_MSR, exit_info_1, 0);
if ((ret == ES_OK) && (!exit_info_1)) {
regs->ax = ghcb->save.rax;
@@ -1452,7 +1451,7 @@ 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, true, ctxt, exit_code, exit_info_1, exit_info_2);
+ return sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, exit_info_1, exit_info_2);
}
/*
@@ -1628,7 +1627,7 @@ 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, true, ctxt, SVM_EXIT_WRITE_DR7, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WRITE_DR7, 0, 0);
if (ret != ES_OK)
return ret;
@@ -1658,7 +1657,7 @@ 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, true, ctxt, SVM_EXIT_WBINVD, 0, 0);
+ return sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WBINVD, 0, 0);
}
static enum es_result vc_handle_rdpmc(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
@@ -1667,7 +1666,7 @@ 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, true, ctxt, SVM_EXIT_RDPMC, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_RDPMC, 0, 0);
if (ret != ES_OK)
return ret;
@@ -1708,7 +1707,7 @@ 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, true, ctxt, SVM_EXIT_VMMCALL, 0, 0);
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_VMMCALL, 0, 0);
if (ret != ES_OK)
return ret;
@@ -2197,7 +2196,7 @@ int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned
ghcb_set_rbx(ghcb, input->data_npages);
}
- ret = sev_es_ghcb_hv_call(ghcb, true, &ctxt, exit_code, input->req_gpa, input->resp_gpa);
+ ret = sev_es_ghcb_hv_call(ghcb, &ctxt, exit_code, input->req_gpa, input->resp_gpa);
if (ret)
goto e_put;
--
2.35.1
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette