On 21/05/2019 14:49, Thiago Jung Bauermann wrote: > From: Ram Pai <linux...@us.ibm.com> > > Make the Enter-Secure-Mode (ESM) ultravisor call to switch the VM to secure > mode. Add "svm=" command line option to turn off switching to secure mode. > Introduce CONFIG_PPC_SVM to control support for secure guests. > > Signed-off-by: Ram Pai <linux...@us.ibm.com> > [ Generate an RTAS os-term hcall when the ESM ucall fails. ] > Signed-off-by: Michael Anderson <andm...@linux.ibm.com> > [ Cleaned up the code a bit. ] > Signed-off-by: Thiago Jung Bauermann <bauer...@linux.ibm.com> > --- > .../admin-guide/kernel-parameters.txt | 5 + > arch/powerpc/include/asm/ultravisor-api.h | 1 + > arch/powerpc/kernel/prom_init.c | 124 ++++++++++++++++++ > 3 files changed, 130 insertions(+) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt > b/Documentation/admin-guide/kernel-parameters.txt > index c45a19d654f3..7237d86b25c6 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -4501,6 +4501,11 @@ > /sys/power/pm_test). Only available when CONFIG_PM_DEBUG > is set. Default value is 5. > > + svm= [PPC] > + Format: { on | off | y | n | 1 | 0 } > + This parameter controls use of the Protected > + Execution Facility on pSeries. > + > swapaccount=[0|1] > [KNL] Enable accounting of swap in memory resource > controller if no parameter or 1 is given or disable > diff --git a/arch/powerpc/include/asm/ultravisor-api.h > b/arch/powerpc/include/asm/ultravisor-api.h > index 15e6ce77a131..0e8b72081718 100644 > --- a/arch/powerpc/include/asm/ultravisor-api.h > +++ b/arch/powerpc/include/asm/ultravisor-api.h > @@ -19,6 +19,7 @@ > > /* opcodes */ > #define UV_WRITE_PATE 0xF104 > +#define UV_ESM 0xF110 > #define UV_RETURN 0xF11C > > #endif /* _ASM_POWERPC_ULTRAVISOR_API_H */ > diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c > index 523bb99d7676..5d8a3efb54f2 100644 > --- a/arch/powerpc/kernel/prom_init.c > +++ b/arch/powerpc/kernel/prom_init.c > @@ -44,6 +44,7 @@ > #include <asm/sections.h> > #include <asm/machdep.h> > #include <asm/asm-prototypes.h> > +#include <asm/ultravisor-api.h> > > #include <linux/linux_logo.h> > > @@ -174,6 +175,10 @@ static unsigned long __prombss prom_tce_alloc_end; > static bool __prombss prom_radix_disable; > #endif > > +#ifdef CONFIG_PPC_SVM > +static bool __prombss prom_svm_disable; > +#endif > + > struct platform_support { > bool hash_mmu; > bool radix_mmu; > @@ -809,6 +814,17 @@ static void __init early_cmdline_parse(void) > if (prom_radix_disable) > prom_debug("Radix disabled from cmdline\n"); > #endif /* CONFIG_PPC_PSERIES */ > + > +#ifdef CONFIG_PPC_SVM > + opt = prom_strstr(prom_cmd_line, "svm="); > + if (opt) { > + bool val; > + > + opt += sizeof("svm=") - 1; > + if (!prom_strtobool(opt, &val)) > + prom_svm_disable = !val; > + } > +#endif /* CONFIG_PPC_SVM */ > } > > #ifdef CONFIG_PPC_PSERIES > @@ -1707,6 +1723,43 @@ static void __init prom_close_stdin(void) > } > } > > +#ifdef CONFIG_PPC_SVM > +static int prom_rtas_os_term_hcall(uint64_t args) This is just an rtas hcall, nothing special about "os-term". > +{ > + register uint64_t arg1 asm("r3") = 0xf000; > + register uint64_t arg2 asm("r4") = args; > + > + asm volatile("sc 1\n" : "=r" (arg1) : > + "r" (arg1), > + "r" (arg2) :); > + return arg1; > +} > + > +static struct rtas_args __prombss os_term_args; > + > +static void __init prom_rtas_os_term(char *str) > +{ > + phandle rtas_node; > + __be32 val; > + u32 token; > + > + prom_printf("%s: start...\n", __func__); > + rtas_node = call_prom("finddevice", 1, 1, ADDR("/rtas")); > + prom_printf("rtas_node: %x\n", rtas_node); > + if (!PHANDLE_VALID(rtas_node)) > + return; > + > + val = 0; > + prom_getprop(rtas_node, "ibm,os-term", &val, sizeof(val)); > + token = be32_to_cpu(val); > + prom_printf("ibm,os-term: %x\n", token); > + if (token == 0) > + prom_panic("Could not get token for ibm,os-term\n"); > + os_term_args.token = cpu_to_be32(token); > + prom_rtas_os_term_hcall((uint64_t)&os_term_args); > +} > +#endif /* CONFIG_PPC_SVM */ > + > /* > * Allocate room for and instantiate RTAS > */ > @@ -3162,6 +3215,74 @@ static void unreloc_toc(void) > #endif > #endif > > +#ifdef CONFIG_PPC_SVM > +/* > + * The ESM blob is a data structure with information needed by the > Ultravisor to > + * validate the integrity of the secure guest. > + */ > +static void *get_esm_blob(void) > +{ > + /* > + * FIXME: We are still finalizing the details on how prom_init will grab > + * the ESM blob. When that is done, this function will be updated. > + */ > + return (void *)0xdeadbeef; > +} > + > +/* > + * Perform the Enter Secure Mode ultracall. > + */ > +static int enter_secure_mode(void *esm_blob, void *retaddr, void *fdt) > +{ > + register uint64_t func asm("r0") = UV_ESM; > + register uint64_t arg1 asm("r3") = (uint64_t)esm_blob; > + register uint64_t arg2 asm("r4") = (uint64_t)retaddr; > + register uint64_t arg3 asm("r5") = (uint64_t)fdt; > + > + asm volatile("sc 2\n" > + : "=r"(arg1) > + : "r"(func), "0"(arg1), "r"(arg2), "r"(arg3) > + :); > + > + return (int)arg1; > +} > + > +/* > + * Call the Ultravisor to transfer us to secure memory if we have an ESM > blob. > + */ > +static void setup_secure_guest(void *fdt) > +{ > + void *esm_blob; > + int ret; > + > + if (prom_svm_disable) { > + prom_printf("Secure mode is OFF\n"); > + return; > + } > + > + esm_blob = get_esm_blob(); > + if (esm_blob == NULL) > + /* > + * Absence of an ESM blob isn't an error, it just means we > + * shouldn't switch to secure mode. > + */ > + return; > + > + /* Switch to secure mode. */ > + prom_printf("Switching to secure mode.\n"); > + > + ret = enter_secure_mode(esm_blob, NULL, fdt); > + if (ret != U_SUCCESS) { > + prom_printf("Returned %d from switching to secure mode.\n", > ret); > + prom_rtas_os_term("Switch to secure mode failed.\n"); > + } > +} > +#else > +static void setup_secure_guest(void *fdt) > +{ > +} > +#endif /* CONFIG_PPC_SVM */ > + > /* > * We enter here early on, when the Open Firmware prom is still > * handling exceptions and the MMU hash table for us. > @@ -3360,6 +3481,9 @@ unsigned long __init prom_init(unsigned long r3, > unsigned long r4, > unreloc_toc(); > #endif > > + /* Move to secure memory if we're supposed to be secure guests. */ > + setup_secure_guest((void *)hdr); > + > __start(hdr, kbase, 0, 0, 0, 0, 0); > > return 0; > -- Alexey